Turn webspeech on/off when tab goes fore/background

chrome/browser/media/media_stream_devices_controller.cc

Index: chrome/browser/media/media_stream_devices_controller.cc
diff --git a/chrome/browser/media/media_stream_devices_controller.cc b/chrome/browser/media/media_stream_devices_controller.cc
index 1103f9af842553ecfca9291206d657caa8c569f8..431af985362b043c48a232b1c535c8c0baebccfb 100644
--- a/chrome/browser/media/media_stream_devices_controller.cc
+++ b/chrome/browser/media/media_stream_devices_controller.cc
@@ -23,6 +23,7 @@
 #include "chrome/common/pref_names.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_widget_host_view.h"
 #include "content/public/common/media_stream_request.h"
 #include "extensions/common/constants.h"
 #include "grit/generated_resources.h"
@@ -662,7 +663,7 @@ bool MediaStreamDevicesController::IsDeviceAudioCaptureRequestedAndAllowed()
     const {
   MediaStreamTypeSettingsMap::const_iterator it =
       request_permissions_.find(content::MEDIA_DEVICE_AUDIO_CAPTURE);
-  return (it != request_permissions_.end() &&
+  return (it != request_permissions_.end() && IsCaptureDeviceRequestAllowed() &&
           it->second.permission == MEDIA_ALLOWED);
 }
 
@@ -670,6 +671,15 @@ bool MediaStreamDevicesController::IsDeviceVideoCaptureRequestedAndAllowed()
     const {
   MediaStreamTypeSettingsMap::const_iterator it =
       request_permissions_.find(content::MEDIA_DEVICE_VIDEO_CAPTURE);
-  return (it != request_permissions_.end() &&
+  return (it != request_permissions_.end() && IsCaptureDeviceRequestAllowed() &&
           it->second.permission == MEDIA_ALLOWED);
 }
+
+bool MediaStreamDevicesController::IsCaptureDeviceRequestAllowed() const {
+#if defined(OS_ANDROID)
+  // Don't approve device requests if the tab was hidden.
+  // TODO(qinmin): Add a test for this. http://crbug.com/396869.
+  return web_contents_->GetRenderWidgetHostView()->IsShowing();
+#endif
+  return true;
+}