diff --git a/BUILD.gn b/BUILD.gn
index 23d79047d6a985..66f617bc675f11 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -304,13 +304,14 @@ group("gn_all") {
       "//testing/android/junit:junit_unit_tests",
       "//third_party/android_async_task:android_async_task_java",
       "//third_party/catapult/devil",
-      "//third_party/errorprone:chromium_errorprone",
+      "//third_party/errorprone:errorprone_java",
       "//third_party/smhasher:murmurhash3",
       "//tools/android:android_tools",
       "//tools/android:memconsumer",
       "//tools/android:push_apps_to_background",
       "//tools/android/audio_focus_grabber:audio_focus_grabber_apk",
       "//tools/android/customtabs_benchmark:customtabs_benchmark_apk",
+      "//tools/android/errorprone_plugin:errorprone_plugin_java",
       "//tools/android/kerberos/SpnegoAuthenticator:spnego_authenticator_apk",
       "//tools/cygprofile:cygprofile_unittests",
       "//ui/android:ui_junit_tests",
diff --git a/DEPS b/DEPS
index 4d80203506cb9a..5f7b5c5a89d337 100644
--- a/DEPS
+++ b/DEPS
@@ -250,6 +250,11 @@ deps = {
       'condition': 'checkout_android',
   },
 
+  'src/third_party/auto/src': {
+      'url': Var('chromium_git') + '/external/github.com/google/auto.git' + '@' + '71802f2ae74dae2744abd999f8434e13055c4ee3',
+      'condition': 'checkout_android',
+  },
+
   'src/third_party/bidichecker':
     Var('chromium_git') + '/external/bidichecker/lib.git' + '@' + '97f2aa645b74c28c57eca56992235c79850fa9e0',
 
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/ContentSettingsAdapter.java b/android_webview/glue/java/src/com/android/webview/chromium/ContentSettingsAdapter.java
index 4aa7a485bb49c9..a64ff3dd86ec09 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/ContentSettingsAdapter.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/ContentSettingsAdapter.java
@@ -19,7 +19,7 @@
  * Type adaptation layer between {@link android.webkit.WebSettings} and
  * {@link org.chromium.android_webview.AwSettings}.
  */
-@SuppressWarnings("deprecation")
+@SuppressWarnings({"deprecation", "NoSynchronizedMethodCheck"})
 @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
 @TargetApi(Build.VERSION_CODES.LOLLIPOP)
 public class ContentSettingsAdapter extends android.webkit.WebSettings {
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/CookieManagerAdapter.java b/android_webview/glue/java/src/com/android/webview/chromium/CookieManagerAdapter.java
index 7ae88a95030b81..77dc95528fb341 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/CookieManagerAdapter.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/CookieManagerAdapter.java
@@ -18,7 +18,7 @@
  * Chromium implementation of CookieManager -- forwards calls to the
  * chromium internal implementation.
  */
-@SuppressWarnings("deprecation")
+@SuppressWarnings({"deprecation", "NoSynchronizedMethodCheck"})
 @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
 public class CookieManagerAdapter extends CookieManager {
     private static final String TAG = "CookieManager";
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/ServiceWorkerSettingsAdapter.java b/android_webview/glue/java/src/com/android/webview/chromium/ServiceWorkerSettingsAdapter.java
index dc22ab2f460822..8698a31ad48da9 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/ServiceWorkerSettingsAdapter.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/ServiceWorkerSettingsAdapter.java
@@ -11,6 +11,7 @@
  * Type adaptation layer between {@link android.webkit.ServiceWorkerWebSettings}
  * and {@link org.chromium.android_webview.AwServiceWorkerSettings}.
  */
+@SuppressWarnings("NoSynchronizedMethodCheck")
 @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
 public class ServiceWorkerSettingsAdapter extends android.webkit.ServiceWorkerWebSettings {
     private AwServiceWorkerSettings mAwServiceWorkerSettings;
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/WebBackForwardListChromium.java b/android_webview/glue/java/src/com/android/webview/chromium/WebBackForwardListChromium.java
index 7b10cabee8cba7..2512a2cde014a5 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/WebBackForwardListChromium.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/WebBackForwardListChromium.java
@@ -17,9 +17,8 @@
  * WebView Chromium implementation of WebBackForwardList. Simple immutable
  * wrapper around NavigationHistory.
  */
-@SuppressFBWarnings({
-        "CHROMIUM_SYNCHRONIZED_METHOD",
-        "SE_BAD_FIELD"})
+@SuppressWarnings("NoSynchronizedMethodCheck")
+@SuppressFBWarnings({"CHROMIUM_SYNCHRONIZED_METHOD", "SE_BAD_FIELD"})
 public class WebBackForwardListChromium extends WebBackForwardList {
     private final List<WebHistoryItemChromium> mHistroryItemList;
     private final int mCurrentIndex;
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/WebHistoryItemChromium.java b/android_webview/glue/java/src/com/android/webview/chromium/WebHistoryItemChromium.java
index d492bdff3a64a5..3303464320c291 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/WebHistoryItemChromium.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/WebHistoryItemChromium.java
@@ -80,12 +80,12 @@ private WebHistoryItemChromium(String url, String originalUrl, String title, Bit
     /**
      * See {@link android.webkit.WebHistoryItem#clone}.
      */
-    @SuppressFBWarnings({
-            "CHROMIUM_SYNCHRONIZED_METHOD",
-            "CN_IDIOM_NO_SUPER_CALL",
+    @SuppressWarnings("NoSynchronizedMethodCheck")
+    @SuppressFBWarnings({"CHROMIUM_SYNCHRONIZED_METHOD", "CN_IDIOM_NO_SUPER_CALL",
             "CN_IMPLEMENTS_CLONE_BUT_NOT_CLONEABLE"})
     @Override
-    public synchronized WebHistoryItemChromium clone() {
+    public synchronized WebHistoryItemChromium
+    clone() {
         return new WebHistoryItemChromium(mUrl, mOriginalUrl, mTitle, mFavicon);
     }
 }
diff --git a/base/android/java/src/org/chromium/base/NonThreadSafe.java b/base/android/java/src/org/chromium/base/NonThreadSafe.java
index 26f6d72fd8a790..2ab654c442274a 100644
--- a/base/android/java/src/org/chromium/base/NonThreadSafe.java
+++ b/base/android/java/src/org/chromium/base/NonThreadSafe.java
@@ -33,6 +33,7 @@ public synchronized void detachFromThread() {
      * Assigns the current thread if no thread was assigned.
      */
     @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
+    @SuppressWarnings("NoSynchronizedMethodCheck")
     public synchronized boolean calledOnValidThread() {
         ensureThreadIdAssigned();
         return mThreadId.equals(Thread.currentThread().getId());
diff --git a/build/android/gyp/jar.py b/build/android/gyp/jar.py
index 2b19c587b78f03..2f54c1ae8d2b71 100755
--- a/build/android/gyp/jar.py
+++ b/build/android/gyp/jar.py
@@ -66,11 +66,11 @@ def Jar(class_files, classes_dir, jar_path, manifest_file=None,
 
 def JarDirectory(classes_dir, jar_path, manifest_file=None, predicate=None,
                  provider_configurations=None, additional_files=None):
-  class_files = build_utils.FindInDirectory(classes_dir, '*.class')
+  all_files = build_utils.FindInDirectory(classes_dir, '*')
   if predicate:
-    class_files = [f for f in class_files if predicate(f)]
+    all_files = [f for f in all_files if predicate(f)]
 
-  Jar(class_files, classes_dir, jar_path, manifest_file=manifest_file,
+  Jar(all_files, classes_dir, jar_path, manifest_file=manifest_file,
       provider_configurations=provider_configurations,
       additional_files=additional_files)
 
diff --git a/build/android/gyp/javac.py b/build/android/gyp/javac.py
index d9921253fdd173..c6134261ab73f4 100755
--- a/build/android/gyp/javac.py
+++ b/build/android/gyp/javac.py
@@ -332,6 +332,9 @@ def _ParseOptions(argv):
       dest='processors',
       action='append',
       help='Annotation processor to use.')
+  parser.add_option(
+      '--processorpath',
+      help='Where javac should look for annotation processors.')
   parser.add_option(
       '--processor-arg',
       dest='processor_args',
@@ -469,6 +472,8 @@ def main(argv):
 
   if options.processors:
     javac_cmd.extend(['-processor', ','.join(options.processors)])
+  if options.processorpath:
+    javac_cmd.extend(['-processorpath', options.processorpath])
   if options.processor_args:
     for arg in options.processor_args:
       javac_cmd.extend(['-A%s' % arg])
diff --git a/build/config/android/internal_rules.gni b/build/config/android/internal_rules.gni
index 2172d48e48be5b..55a2920c62ec13 100644
--- a/build/config/android/internal_rules.gni
+++ b/build/config/android/internal_rules.gni
@@ -2541,10 +2541,14 @@ if (enable_java_templates) {
         args += [ "--chromium-code=1" ]
       }
       if (_enable_errorprone) {
-        deps += [ "//third_party/errorprone:chromium_errorprone($default_toolchain)" ]
+        deps +=
+            [ "//third_party/errorprone:errorprone_java($default_toolchain)" ]
+        deps += [ "//tools/android/errorprone_plugin:errorprone_plugin_java($default_toolchain)" ]
         args += [
           "--use-errorprone-path",
-          "bin/chromium_errorprone",
+          "bin/errorprone_java",
+          "--processorpath",
+          "lib.java/tools/android/errorprone_plugin/errorprone_plugin_java.jar",
         ]
       }
       foreach(e, _provider_configurations) {
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java
index c53ba8972de9e4..e189c2356a5b64 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java
@@ -8,7 +8,6 @@
 import android.os.StrictMode;
 
 import org.chromium.base.ContextUtils;
-import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.ChromeVersionInfo;
 import org.chromium.chrome.browser.crash.MinidumpUploadService.ProcessType;
@@ -70,7 +69,7 @@ public class ChromePreferenceManager {
 
     public static final String CHROME_HOME_SHARED_PREFERENCES_KEY = "chrome_home_enabled_date";
 
-    private static ChromePreferenceManager sPrefs;
+    private static ChromePreferenceManager sPrefs = new ChromePreferenceManager();
 
     private final SharedPreferences mSharedPreferences;
 
@@ -82,11 +81,7 @@ private ChromePreferenceManager() {
      * Get the static instance of ChromePreferenceManager if exists else create it.
      * @return the ChromePreferenceManager singleton
      */
-    @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
-    public static synchronized ChromePreferenceManager getInstance() {
-        if (sPrefs == null) {
-            sPrefs = new ChromePreferenceManager();
-        }
+    public static ChromePreferenceManager getInstance() {
         return sPrefs;
     }
 
diff --git a/components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java b/components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java
index 08a7036845f8b4..c3e725f767aa3b 100644
--- a/components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java
+++ b/components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java
@@ -189,6 +189,7 @@ private abstract class BridgeAsyncTask<Result> {
         public void execute() {
             AsyncTask<Void, Void, Result> task = new AsyncTask<Void, Void, Result>() {
                 @Override
+                @SuppressWarnings("NoSynchronizedThisCheck") // Only used/accessible by native.
                 protected Result doInBackground(Void... params) {
                     synchronized (InstanceIDBridge.this) {
                         if (mInstanceID == null) {
diff --git a/third_party/.gitignore b/third_party/.gitignore
index 777630ba97b4df..24cf2103537024 100644
--- a/third_party/.gitignore
+++ b/third_party/.gitignore
@@ -24,6 +24,7 @@
 /apache-win32/modules/*.dll
 /apk-patch-size-estimator/lib/*.jar
 /asan
+/auto/src
 /bazel/desugar/Desugar.jar
 /bidichecker
 /bison
diff --git a/third_party/auto/BUILD.gn b/third_party/auto/BUILD.gn
new file mode 100644
index 00000000000000..56b283e2fd0e1f
--- /dev/null
+++ b/third_party/auto/BUILD.gn
@@ -0,0 +1,36 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+java_library("auto_common_java") {
+  java_files = [
+    "src/common/src/main/java/com/google/auto/common/AnnotationMirrors.java",
+    "src/common/src/main/java/com/google/auto/common/BasicAnnotationProcessor.java",
+    "src/common/src/main/java/com/google/auto/common/MoreTypes.java",
+    "src/common/src/main/java/com/google/auto/common/SuperficialValidation.java",
+    "src/common/src/main/java/com/google/auto/common/AnnotationValues.java",
+    "src/common/src/main/java/com/google/auto/common/MoreElements.java",
+    "src/common/src/main/java/com/google/auto/common/Overrides.java",
+    "src/common/src/main/java/com/google/auto/common/Visibility.java",
+  ]
+
+  deps = [
+    "//third_party/guava:guava_java",
+  ]
+}
+
+java_library("auto_service_java") {
+  java_files = [
+    "src/service/src/main/java/com/google/auto/service/AutoService.java",
+    "src/service/src/main/java/com/google/auto/service/processor/AutoServiceProcessor.java",
+    "src/service/src/main/java/com/google/auto/service/processor/package-info.java",
+    "src/service/src/main/java/com/google/auto/service/processor/ServicesFiles.java",
+  ]
+
+  deps = [
+    ":auto_common_java",
+    "//third_party/guava:guava_java",
+  ]
+}
diff --git a/third_party/auto/OWNERS b/third_party/auto/OWNERS
new file mode 100644
index 00000000000000..80e6172b625a52
--- /dev/null
+++ b/third_party/auto/OWNERS
@@ -0,0 +1,3 @@
+agrieve@chromium.org
+nyquist@chromium.org
+wnwen@chromium.org
diff --git a/third_party/auto/README.chromium b/third_party/auto/README.chromium
new file mode 100644
index 00000000000000..008a3eab20e2c0
--- /dev/null
+++ b/third_party/auto/README.chromium
@@ -0,0 +1,15 @@
+Name: Auto
+Short Name: auto
+URL: https://github.com/google/auto
+Version: 71802f2ae74dae2744abd999f8434e13055c4ee3
+Date: November 1, 2017
+License: Apache 2.0
+License File: NOT_SHIPPED
+Security Critical: no
+
+Description:
+* A collection of source code generators for Java.
+* AutoService used for custom plugins in //tools/android/errorprone_plugin.
+
+Local Modifications:
+* Add BUILD.gn.
diff --git a/third_party/errorprone/BUILD.gn b/third_party/errorprone/BUILD.gn
index bac14b93ee8d9c..13b2e418cb9b89 100644
--- a/third_party/errorprone/BUILD.gn
+++ b/third_party/errorprone/BUILD.gn
@@ -5,7 +5,7 @@
 import("//build/config/android/rules.gni")
 
 if (current_toolchain == default_toolchain) {
-  java_prebuilt("chromium_errorprone") {
+  java_prebuilt("errorprone_java") {
     jar_path = "lib/error_prone_ant-2.0.15.jar"
     main_class = "com.google.errorprone.ErrorProneCompiler"
   }
diff --git a/third_party/errorprone/OWNERS b/third_party/errorprone/OWNERS
index 56e1e2841991b2..e4f73890b27e53 100644
--- a/third_party/errorprone/OWNERS
+++ b/third_party/errorprone/OWNERS
@@ -1,3 +1,4 @@
 agrieve@chromium.org
 jbudorick@chromium.org
+nyquist@chromium.org
 wnwen@chromium.org
diff --git a/third_party/errorprone/README.chromium b/third_party/errorprone/README.chromium
index 809b3404ff2b36..18210b2deda636 100644
--- a/third_party/errorprone/README.chromium
+++ b/third_party/errorprone/README.chromium
@@ -4,7 +4,7 @@ URL: http://errorprone.info/
 Version: 2.0.15
 Date: October 18, 2017
 License: Apache 2.0
-License File: LICENSE
+License File: NOT_SHIPPED
 Security Critical: no
 
 Description:
diff --git a/third_party/guava/BUILD.gn b/third_party/guava/BUILD.gn
index 8b798b4b83b10a..fdadb226a1466c 100644
--- a/third_party/guava/BUILD.gn
+++ b/third_party/guava/BUILD.gn
@@ -5,7 +5,13 @@
 import("//build/config/android/rules.gni")
 
 java_prebuilt("guava_java") {
-  testonly = true
+  # Since our build tooling depends on this target, we need it to not be
+  # "testonly = true", but production code must not depend on this as it
+  # results in size regressions. Thus, do not use this outside of tests and
+  # build tooling.
   supports_android = true
   jar_path = "lib/guava-20.0.jar"
+
+  # Avoids dependency cycle.
+  no_build_hooks = true
 }
diff --git a/tools/android/errorprone_plugin/BUILD.gn b/tools/android/errorprone_plugin/BUILD.gn
new file mode 100644
index 00000000000000..b15ff20d0d8fa7
--- /dev/null
+++ b/tools/android/errorprone_plugin/BUILD.gn
@@ -0,0 +1,23 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+java_library("errorprone_plugin_java") {
+  java_files = [
+    "src/org/chromium/tools/errorprone/plugin/NoSynchronizedMethodCheck.java",
+    "src/org/chromium/tools/errorprone/plugin/NoSynchronizedThisCheck.java",
+  ]
+
+  processors_javac =
+      [ "com.google.auto.service.processor.AutoServiceProcessor" ]
+
+  # Necessary to avoid dependency cycle
+  enable_errorprone = false
+
+  deps = [
+    "//third_party/auto:auto_service_java",
+    "//third_party/errorprone:errorprone_java",
+  ]
+}
diff --git a/tools/android/errorprone_plugin/OWNERS b/tools/android/errorprone_plugin/OWNERS
new file mode 100644
index 00000000000000..80e6172b625a52
--- /dev/null
+++ b/tools/android/errorprone_plugin/OWNERS
@@ -0,0 +1,3 @@
+agrieve@chromium.org
+nyquist@chromium.org
+wnwen@chromium.org
diff --git a/tools/android/errorprone_plugin/src/org/chromium/tools/errorprone/plugin/NoSynchronizedMethodCheck.java b/tools/android/errorprone_plugin/src/org/chromium/tools/errorprone/plugin/NoSynchronizedMethodCheck.java
new file mode 100644
index 00000000000000..b99f1871e52053
--- /dev/null
+++ b/tools/android/errorprone_plugin/src/org/chromium/tools/errorprone/plugin/NoSynchronizedMethodCheck.java
@@ -0,0 +1,52 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.tools.errorprone.plugin;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.fixes.SuggestedFixes;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.MethodTree;
+import com.sun.tools.javac.code.Symbol;
+
+import javax.lang.model.element.Modifier;
+
+/**
+ * Triggers an error for public methods that use "synchronized" in their signature.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(name = "NoSynchronizedMethodCheck", category = BugPattern.Category.JDK,
+        summary = "Use of synchronized in public method signature disallowed.",
+        severity = BugPattern.SeverityLevel.ERROR, linkType = BugPattern.LinkType.CUSTOM,
+        link = "https://stackoverflow.com/questions/20906548/why-is-synchronized-block-better-than-synchronized-method")
+public class NoSynchronizedMethodCheck extends BugChecker implements BugChecker.MethodTreeMatcher {
+    @Override
+    public Description matchMethod(MethodTree methodTree, VisitorState visitorState) {
+        Symbol.MethodSymbol method = ASTHelpers.getSymbol(methodTree);
+        // Skip methods that aren't synchronized and non-public methods
+        if (!method.getModifiers().contains(Modifier.SYNCHRONIZED)
+                || !method.getModifiers().contains(Modifier.PUBLIC)) {
+            return Description.NO_MATCH;
+        }
+        // Skip methods that are only public due to VisibleForTesting
+        if (ASTHelpers.hasDirectAnnotationWithSimpleName(method, "VisibleForTesting")) {
+            return Description.NO_MATCH;
+        }
+        // Skip non-public classes
+        Symbol.ClassSymbol enclosingClass = ASTHelpers.enclosingClass(method);
+        if (!enclosingClass.getModifiers().contains(Modifier.PUBLIC)) {
+            return Description.NO_MATCH;
+        }
+        return buildDescription(methodTree)
+                .addFix(SuggestedFixes.removeModifiers(
+                        methodTree, visitorState, Modifier.SYNCHRONIZED))
+                .setMessage(String.format(
+                        "Used synchronized modifier in public method %s", method.getSimpleName()))
+                .build();
+    }
+}
diff --git a/tools/android/errorprone_plugin/src/org/chromium/tools/errorprone/plugin/NoSynchronizedThisCheck.java b/tools/android/errorprone_plugin/src/org/chromium/tools/errorprone/plugin/NoSynchronizedThisCheck.java
new file mode 100644
index 00000000000000..f82664e567c61d
--- /dev/null
+++ b/tools/android/errorprone_plugin/src/org/chromium/tools/errorprone/plugin/NoSynchronizedThisCheck.java
@@ -0,0 +1,46 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.tools.errorprone.plugin;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.SynchronizedTree;
+import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.tree.JCTree;
+import com.sun.tools.javac.tree.TreeInfo;
+
+import javax.lang.model.element.Modifier;
+
+/**
+ * This class detects the synchronized method.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(name = "NoSynchronizedThisCheck", category = BugPattern.Category.JDK,
+        summary = "Do not synchronized on 'this' in public classes",
+        severity = BugPattern.SeverityLevel.ERROR, linkType = BugPattern.LinkType.CUSTOM,
+        link = "https://stackoverflow.com/questions/442564/avoid-synchronizedthis-in-java")
+public class NoSynchronizedThisCheck
+        extends BugChecker implements BugChecker.SynchronizedTreeMatcher {
+    @Override
+    public Description matchSynchronized(SynchronizedTree tree, VisitorState visitorState) {
+        Symbol lock = ASTHelpers.getSymbol(TreeInfo.skipParens((JCTree) tree.getExpression()));
+        // Skip locks that are not 'this'
+        if (!lock.getSimpleName().contentEquals("this")) {
+            return Description.NO_MATCH;
+        }
+        // Skip non-public classes
+        Symbol.ClassSymbol enclosingClass = ASTHelpers.enclosingClass(lock);
+        if (!enclosingClass.getModifiers().contains(Modifier.PUBLIC)) {
+            return Description.NO_MATCH;
+        }
+        return buildDescription(tree)
+                .setMessage("Used instance variable as synchronization lock")
+                .build();
+    }
+}