Fix VR module native code with isolated splits

There were three separate issues which were preventing the VR native
code from working correctly:
- Isolated split class loaders can't load native libraries (b/171269960)
- Shared libs for modules were not being added to the module descriptor
- The GVR native methods need to be manually registered now that GVR
  code is not in the base module.

Bug: 1126301
Change-Id: I184ea61fe4ef97a598ecf47b6e3cd81f4425ec1f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2486571
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819164}

base/android/java/src/org/chromium/base/BundleUtils.java

@@ -98,10 +98,24 @@ public static Context createIsolatedSplitContext(Context base, String splitName)
 
     /* Returns absolute path to a native library in a feature module. */
     @CalledByNative
-    private static String getNativeLibraryPath(String libraryName) {
+    public static String getNativeLibraryPath(String libraryName) {
         try (StrictModeContext ignored = StrictModeContext.allowDiskReads()) {
-            return ((BaseDexClassLoader) ContextUtils.getApplicationContext().getClassLoader())
-                    .findLibrary(libraryName);
+            ClassLoader classLoader = ContextUtils.getApplicationContext().getClassLoader();
+            String path = getNativeLibraryPathFromClassLoader(classLoader, libraryName);
+            // TODO(b/171269960): Isolated split class loaders have an empty library path, so check
+            // the parent class loader as well.
+            if (path == null) {
+                path = getNativeLibraryPathFromClassLoader(classLoader.getParent(), libraryName);
+            }
+            return path;
         }
     }
+
+    private static String getNativeLibraryPathFromClassLoader(
+            ClassLoader classLoader, String libraryName) {
+        if (classLoader == null) {
+            return null;
+        }
+        return ((BaseDexClassLoader) classLoader).findLibrary(libraryName);
+    }
 }

chrome/android/java/src/org/chromium/chrome/browser/vr/ArCoreJavaUtils.java

@@ -8,11 +8,9 @@
 import android.content.Context;
 import android.view.Surface;
 
-import dalvik.system.BaseDexClassLoader;
-
+import org.chromium.base.BundleUtils;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
-import org.chromium.base.StrictModeContext;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
@@ -65,10 +63,7 @@ private static ArCoreJavaUtils create(long nativeArCoreJavaUtils) {
 
     @CalledByNative
     private static String getArCoreShimLibraryPath() {
-        try (StrictModeContext ignored = StrictModeContext.allowDiskReads()) {
-            return ((BaseDexClassLoader) ContextUtils.getApplicationContext().getClassLoader())
-                    .findLibrary("arcore_sdk_c");
-        }
+        return BundleUtils.getNativeLibraryPath("arcore_sdk_c");
     }
 
     /**

chrome/android/modules/chrome_bundle_tmpl.gni

@@ -48,10 +48,25 @@ template("chrome_bundle") {
           _module_desc.supports_isolated_split) {
         _module_descs += [ _module_desc ]
       } else {
+        _shared_libraries = []
+        if (defined(_module_desc.native_deps) &&
+            _module_desc.native_deps != []) {
+          _arch = ""
+          _toolchain = ""
+          if (android_64bit_target_cpu) {
+            if (invoker.is_64_bit_browser) {
+              _arch = "_64"
+            } else {
+              _toolchain = "($android_secondary_abi_toolchain)"
+            }
+          }
+          _shared_libraries += [ "//chrome/android:libmonochrome${_arch}_${_module_desc.name}${_toolchain}" ]
+        }
         _module_desc_target_name =
             "${target_name}__${_module_desc.name}__module_desc_java"
         module_desc_java(_module_desc_target_name) {
           module_name = _module_desc.name
+          shared_libraries = _shared_libraries
           if (defined(_module_desc.pak_deps)) {
             paks = _module_desc.paks
           }

chrome/browser/android/vr/register_jni_monochrome.cc

@@ -4,9 +4,24 @@
 
 #include "chrome/browser/android/vr/register_jni.h"
 
+#include "chrome/browser/android/vr/register_gvr_jni.h"
+
 namespace vr {
 
 bool RegisterJni(JNIEnv* env) {
+  // The GVR Java code is normally in the vr DFM, which will be loaded into the
+  // base class loader. If the enable_chrome_module gn arg is enabled, the GVR
+  // Java code will be in the chrome DFM, which is loaded as an isolated split.
+  // This means the Java code is no longer automatically loaded in the base
+  // class loader. Automatic JNI registration only works for native methods
+  // associated with the base class loader (which loaded libmonochrome.so, so
+  // will look for symbols there). Most of Chrome's native methods are in
+  // GEN_JNI.java which is present in the base module, so do not need manual
+  // registration. Since GVR has native methods outside of GEN_JNI.java which
+  // are not present in the base module, these must be manually registered.
+  if (!vr::RegisterGvrJni(env)) {
+    return false;
+  }
   return true;
 }