Enable WebAudio support on Android/x86.

content/child/runtime_features.cc

Index: content/child/runtime_features.cc
diff --git a/content/child/runtime_features.cc b/content/child/runtime_features.cc
index 133a366f40fb13492a983c4ff609c97067816e2a..7aa0c7c6b4d238d7e29218b4d52c722dadda9925 100644
--- a/content/child/runtime_features.cc
+++ b/content/child/runtime_features.cc
@@ -27,12 +27,11 @@ static void SetRuntimeFeatureDefaultsForPlatform() {
     WebRuntimeFeatures::enablePrefixedEncryptedMedia(false);
   }
 #endif  // !defined(GOOGLE_TV)
-  bool enable_webaudio = false;
-#if defined(ARCH_CPU_ARMEL)
-  // WebAudio needs Android MediaCodec API
-  enable_webaudio = media::MediaCodecBridge::IsAvailable();
-#endif  // defined(ARCH_CPU_ARMEL)
-  WebRuntimeFeatures::enableWebAudio(enable_webaudio);
+  // WebAudio is enabled by default only on ARM and only when the
+  // MediaCodec API is available.
+  WebRuntimeFeatures::enableWebAudio(
+      media::MediaCodecBridge::IsAvailable() &&
+      (android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM));
   // Android does not support the Gamepad API.
   WebRuntimeFeatures::enableGamepad(false);
   // Android does not have support for PagePopup
@@ -95,8 +94,25 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
   if (command_line.HasSwitch(switches::kEnableServiceWorker))
     WebRuntimeFeatures::enableServiceWorker(true);
 
+#if defined(OS_ANDROID)
+  // WebAudio requires the MediaCodec API.
+#if defined(ARCH_CPU_X86)
+  // WebAudio is disabled by default on x86.
+  WebRuntimeFeatures::enableWebAudio(
+      command_line.HasSwitch(switches::kEnableWebAudio) &&
+      media::MediaCodecBridge::IsAvailable());
+#elif defined(ARCH_CPU_ARMEL)
+  // WebAudio is enabled by default on ARM.
+  WebRuntimeFeatures::enableWebAudio(
+      !command_line.HasSwitch(switches::kDisableWebAudio) &&
+      media::MediaCodecBridge::IsAvailable());
+#else
+  WebRuntimeFeatures::enableWebAudio(false);
+#endif
+#else
   if (command_line.HasSwitch(switches::kDisableWebAudio))
     WebRuntimeFeatures::enableWebAudio(false);
+#endif
 
   if (command_line.HasSwitch(switches::kDisableFullScreen))
     WebRuntimeFeatures::enableFullscreen(false);