diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 164b97d26260f3..584f72be2e30c6 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -881,6 +881,20 @@ config("wexit_time_destructors") {
   }
 }
 
+# On Windows compiling on x64, VC will issue a warning when converting
+# size_t to int because it will truncate the value. Our code should not have
+# these warnings and one should use a static_cast or a checked_cast for the
+# conversion depending on the case. However, a lot of code still needs to be
+# fixed. Apply this config to such targets to disable the warning.
+#
+# Note that this can be applied regardless of platform and architecture to
+# clean up the call sites. This will only apply the flag when necessary.
+config("no_size_t_to_int_warning") {
+  if (is_win && cpu_arch == "x64") {
+    cflags = [ "/wd4267" ]
+  }
+}
+
 # Optimization -----------------------------------------------------------------
 #
 # Note that BUILDCONFIG.gn sets up a variable "default_optimization_config"
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 01a3a6c7d00662..cac0942b6a9806 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -697,6 +697,8 @@ source_set("test_support") {
     "test/tiled_layer_test_common.h",
   ]
 
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   include_dirs = [
     ".",
     "test",
diff --git a/chrome/service/BUILD.gn b/chrome/service/BUILD.gn
index 8ad6a1336f5b84..fe26068d3f3a2d 100644
--- a/chrome/service/BUILD.gn
+++ b/chrome/service/BUILD.gn
@@ -46,6 +46,8 @@ static_library("service") {
     "service_process_prefs.h",
   ]
 
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   deps = [
     "//chrome:strings",
     "//chrome/common",
diff --git a/components/content_settings/core/browser/BUILD.gn b/components/content_settings/core/browser/BUILD.gn
index 89f3ec8834b0c3..a321cbb68d095c 100644
--- a/components/content_settings/core/browser/BUILD.gn
+++ b/components/content_settings/core/browser/BUILD.gn
@@ -40,6 +40,8 @@ static_library("browser") {
     "//net",
     "//url",
   ]
+
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }
 
 source_set("unit_tests") {
diff --git a/components/history/core/browser/BUILD.gn b/components/history/core/browser/BUILD.gn
index c2e1bde87f419d..5e8b4f49ef98ee 100644
--- a/components/history/core/browser/BUILD.gn
+++ b/components/history/core/browser/BUILD.gn
@@ -111,6 +111,8 @@ static_library("browser") {
       "android/visit_sql_handler.h",
     ]
   }
+
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }
 
 proto_library("proto") {
diff --git a/components/url_matcher/BUILD.gn b/components/url_matcher/BUILD.gn
index 83f95d31f04782..7df189b501f1eb 100644
--- a/components/url_matcher/BUILD.gn
+++ b/components/url_matcher/BUILD.gn
@@ -29,4 +29,6 @@ component("url_matcher") {
     "//third_party/re2",
     "//url",
   ]
+
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }
diff --git a/components/web_cache/browser/BUILD.gn b/components/web_cache/browser/BUILD.gn
index d001973974e26c..b9ba85bd634c82 100644
--- a/components/web_cache/browser/BUILD.gn
+++ b/components/web_cache/browser/BUILD.gn
@@ -9,6 +9,8 @@ static_library("browser") {
     "web_cache_manager.h",
   ]
 
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   deps = [
     "//base",
     "//components/web_cache/common",
diff --git a/content/child/BUILD.gn b/content/child/BUILD.gn
index 935db3f86c9ccd..1380fe11869fba 100644
--- a/content/child/BUILD.gn
+++ b/content/child/BUILD.gn
@@ -97,7 +97,10 @@ source_set("child") {
     }
   }
 
-  configs += [ "//content:content_implementation" ]
+  configs += [
+    "//content:content_implementation",
+    "//build/config/compiler:no_size_t_to_int_warning",
+  ]
 
   if (is_ios) {
     # iOS only needs a small portion of content; exclude all the
diff --git a/content/common/BUILD.gn b/content/common/BUILD.gn
index 6bf0f6417f5645..9ca66d2428bf3a 100644
--- a/content/common/BUILD.gn
+++ b/content/common/BUILD.gn
@@ -130,7 +130,10 @@ source_set("common") {
                         ".",
                         "//content")
 
-  configs += [ "//content:content_implementation" ]
+  configs += [
+    "//content:content_implementation",
+    "//build/config/compiler:no_size_t_to_int_warning",
+  ]
 
   public_deps = [
     "//gpu/command_buffer/common",
@@ -453,6 +456,11 @@ source_set("common") {
       ]
     }
   }
+
+  if (is_win && cpu_arch == "x64") {
+    # TODO(jschuh): Remove this after crbug.com/173851 gets fixed.
+    cflags = [ "/bigobj" ]
+  }
 }
 
 mojom("mojo_bindings") {
diff --git a/content/ppapi_plugin/broker_process_dispatcher.cc b/content/ppapi_plugin/broker_process_dispatcher.cc
index 35d5b9d48e639e..97d425043c8824 100644
--- a/content/ppapi_plugin/broker_process_dispatcher.cc
+++ b/content/ppapi_plugin/broker_process_dispatcher.cc
@@ -309,14 +309,16 @@ bool BrokerProcessDispatcher::SetSitePermission(
 
   if (flash_browser_operations_1_3_) {
     PP_Bool result = flash_browser_operations_1_3_->SetSitePermission(
-        data_str.c_str(), setting_type, sites.size(), site_array.get());
+        data_str.c_str(), setting_type,
+        static_cast<uint32_t>(sites.size()), site_array.get());
 
     return PP_ToBool(result);
   }
 
   if (flash_browser_operations_1_2_) {
     PP_Bool result = flash_browser_operations_1_2_->SetSitePermission(
-        data_str.c_str(), setting_type, sites.size(), site_array.get());
+        data_str.c_str(), setting_type,
+        static_cast<uint32_t>(sites.size()), site_array.get());
 
     return PP_ToBool(result);
   }
diff --git a/content/renderer/BUILD.gn b/content/renderer/BUILD.gn
index 1d6430547ad1a5..73445e17a07da6 100644
--- a/content/renderer/BUILD.gn
+++ b/content/renderer/BUILD.gn
@@ -16,7 +16,10 @@ source_set("renderer") {
                         ".",
                         "//content")
 
-  configs += [ "//content:content_implementation" ]
+  configs += [
+    "//content:content_implementation",
+    "//build/config/compiler:no_size_t_to_int_warning",
+  ]
 
   deps = [
     # TODO(GYP) bug 376846 remove this. This should be inherited from //net but
diff --git a/jingle/BUILD.gn b/jingle/BUILD.gn
index 1940dfc9352808..ce66666ca37097 100644
--- a/jingle/BUILD.gn
+++ b/jingle/BUILD.gn
@@ -21,6 +21,8 @@ if (enable_webrtc || !is_android) {
       "//base/third_party/dynamic_annotations",
       "//net",
     ]
+
+    configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
   }
 
   # A library for sending and receiving peer-issued notifications.
diff --git a/media/audio/BUILD.gn b/media/audio/BUILD.gn
index fa9a65781e8ffb..028fd45d027f3c 100644
--- a/media/audio/BUILD.gn
+++ b/media/audio/BUILD.gn
@@ -243,6 +243,8 @@ source_set("audio") {
       sources += get_target_outputs(":pulse_generate_stubs")
     }
   }
+
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }
 
 source_set("test_support") {
diff --git a/media/base/BUILD.gn b/media/base/BUILD.gn
index 138d1f5d661290..0fb3b1ceca8794 100644
--- a/media/base/BUILD.gn
+++ b/media/base/BUILD.gn
@@ -250,6 +250,8 @@ source_set("base") {
     ]
   }
 
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   if (is_linux || is_win) {
     sources += [
       "keyboard_event_counter.cc",
diff --git a/remoting/protocol/BUILD.gn b/remoting/protocol/BUILD.gn
index 3ffcb08d02d5b8..34b38af0224fae 100644
--- a/remoting/protocol/BUILD.gn
+++ b/remoting/protocol/BUILD.gn
@@ -11,7 +11,10 @@ static_library("protocol") {
   sources =
       rebase_path(gypi_values.remoting_protocol_sources, ".", "//remoting")
 
-  configs += [ "//build/config/compiler:wexit_time_destructors" ]
+  configs += [
+    "//build/config/compiler:no_size_t_to_int_warning",
+    "//build/config/compiler:wexit_time_destructors",
+  ]
 
   public_deps = [
     "//third_party/libjingle",