Introduce "disable-speech-api" content flag and add it to WebView.

We don't want to expose Web Speech API in WebView,
because it is not supported there.

NOTE:
This patch should land after crrev.com/1129213002 (blink-side)

BUG=483889

Review URL: https://codereview.chromium.org/1127363004

Cr-Commit-Position: refs/heads/master@{#329645}

android_webview/lib/main/aw_main_delegate.cc

@@ -90,6 +90,9 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   // WebView does not yet support screen orientation locking.
   cl->AppendSwitch(switches::kDisableScreenOrientationLock);
 
+  // WebView does not currently support Web Speech API (crbug.com/487255)
+  cl->AppendSwitch(switches::kDisableSpeechAPI);
+
   // WebView does not (yet) save Chromium data during shutdown, so add setting
   // for Chrome to aggressively persist DOM Storage to minimize data loss.
   // http://crbug.com/479767

content/browser/renderer_host/render_process_host_impl.cc

@@ -1231,6 +1231,7 @@ void RenderProcessHostImpl::PropagateBrowserCommandLineToRenderer(
     switches::kDisablePrefixedEncryptedMedia,
     switches::kDisableSeccompFilterSandbox,
     switches::kDisableSharedWorkers,
+    switches::kDisableSpeechAPI,
     switches::kDisableSVG1DOM,
     switches::kDisableThreadedCompositing,
     switches::kDisableThreadedScrolling,

content/child/runtime_features.cc

@@ -124,6 +124,9 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
     WebRuntimeFeatures::enableWebAudio(false);
 #endif
 
+  if (command_line.HasSwitch(switches::kDisableSpeechAPI))
+    WebRuntimeFeatures::enableScriptedSpeech(false);
+
   if (command_line.HasSwitch(switches::kDisableEncryptedMedia))
     WebRuntimeFeatures::enableEncryptedMedia(false);
 

content/public/common/content_switches.cc

@@ -242,6 +242,9 @@ const char kDisableSmoothScrolling[]        = "disable-smooth-scrolling";
 // Disables the use of a 3D software rasterizer.
 const char kDisableSoftwareRasterizer[]     = "disable-software-rasterizer";
 
+// Disables the Web Speech API.
+const char kDisableSpeechAPI[]                 = "disable-speech-api";
+
 // Disables SVG 1.1 DOM.
 const char kDisableSVG1DOM[]                = "disable-svg1dom";
 

content/public/common/content_switches.h

@@ -81,6 +81,7 @@ CONTENT_EXPORT extern const char kDisableSharedWorkers[];
 CONTENT_EXPORT extern const char kDisableSingleThreadProxyScheduler[];
 CONTENT_EXPORT extern const char kDisableSmoothScrolling[];
 CONTENT_EXPORT extern const char kDisableSoftwareRasterizer[];
+CONTENT_EXPORT extern const char kDisableSpeechAPI[];
 CONTENT_EXPORT extern const char kDisableSVG1DOM[];
 CONTENT_EXPORT extern const char kDisableTextBlobs[];
 CONTENT_EXPORT extern const char kDisableThreadedCompositing[];