Tab audio mute control (views UI), behind a switch (off by default).

chrome/browser/ui/tabs/tab_utils.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/tabs/tab_utils.h"
 
+#include "base/command_line.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/media/media_capture_devices_dispatcher.h"
 #include "chrome/browser/media/media_stream_capture_indicator.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/web_contents.h"
 #include "grit/theme_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/animation/multi_animation.h"
 
 namespace chrome {
 
 namespace {
@@ skipping 107 matching lines @@
   scoped_refptr<MediaStreamCaptureIndicator> indicator =
       MediaCaptureDevicesDispatcher::GetInstance()->
           GetMediaStreamCaptureIndicator();
   if (indicator.get()) {
     if (indicator->IsBeingMirrored(contents))
       return TAB_MEDIA_STATE_CAPTURING;
     if (indicator->IsCapturingUserMedia(contents))
       return TAB_MEDIA_STATE_RECORDING;
   }
 
+  if (IsTabAudioMutingFeatureEnabled() && contents->IsAudioMuted())
+    return TAB_MEDIA_STATE_AUDIO_MUTING;
   if (IsPlayingAudio(contents))
     return TAB_MEDIA_STATE_AUDIO_PLAYING;
 
   return TAB_MEDIA_STATE_NONE;
 }
 
 const gfx::Image& GetTabMediaIndicatorImage(TabMediaState media_state) {
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
   switch (media_state) {
     case TAB_MEDIA_STATE_AUDIO_PLAYING:
       return rb.GetNativeImageNamed(IDR_TAB_AUDIO_INDICATOR);
+    case TAB_MEDIA_STATE_AUDIO_MUTING:
+      return rb.GetNativeImageNamed(IDR_TAB_AUDIO_MUTING_INDICATOR);
     case TAB_MEDIA_STATE_RECORDING:
       return rb.GetNativeImageNamed(IDR_TAB_RECORDING_INDICATOR);
     case TAB_MEDIA_STATE_CAPTURING:
       return rb.GetNativeImageNamed(IDR_TAB_CAPTURE_INDICATOR);
     case TAB_MEDIA_STATE_NONE:
       break;
   }
   NOTREACHED();
   return rb.GetNativeImageNamed(IDR_SAD_FAVICON);
 }
 
+const gfx::Image& GetTabMediaIndicatorAffordanceImage(
+    TabMediaState media_state) {
+  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
+  switch (media_state) {
+    case TAB_MEDIA_STATE_AUDIO_PLAYING:
+    case TAB_MEDIA_STATE_AUDIO_MUTING:
+      return rb.GetNativeImageNamed(IDR_TAB_AUDIO_MUTING_AFFORDANCE);
+    default:

[sky, 2014/09/23 22:58:17]

Can you explicitly list the states so that you get a compile error when a new
one is added (like you have on 241)?

[miu, 2014/09/24 22:34:15]

Done.

+      return GetTabMediaIndicatorImage(media_state);
+  }
+}
+
 scoped_ptr<gfx::Animation> CreateTabMediaIndicatorFadeAnimation(
     TabMediaState media_state) {
   if (media_state == TAB_MEDIA_STATE_RECORDING ||
       media_state == TAB_MEDIA_STATE_CAPTURING) {
     return TabRecordingIndicatorAnimation::Create().PassAs<gfx::Animation>();
   }
 
   // Note: While it seems silly to use a one-part MultiAnimation, it's the only
   // gfx::Animation implementation that lets us control the frame interval.
   gfx::MultiAnimation::Parts parts;
@@ skipping 15 matching lines @@
     return title;
 
   base::string16 result = title;
   if (!result.empty())
     result.append(1, '\n');
   switch (media_state) {
     case TAB_MEDIA_STATE_AUDIO_PLAYING:
       result.append(
           l10n_util::GetStringUTF16(IDS_TOOLTIP_TAB_MEDIA_STATE_AUDIO_PLAYING));
       break;
+    case TAB_MEDIA_STATE_AUDIO_MUTING:
+      result.append(
+          l10n_util::GetStringUTF16(IDS_TOOLTIP_TAB_MEDIA_STATE_AUDIO_MUTING));
+      break;
     case TAB_MEDIA_STATE_RECORDING:
       result.append(
           l10n_util::GetStringUTF16(IDS_TOOLTIP_TAB_MEDIA_STATE_RECORDING));
       break;
     case TAB_MEDIA_STATE_CAPTURING:
       result.append(
           l10n_util::GetStringUTF16(IDS_TOOLTIP_TAB_MEDIA_STATE_CAPTURING));
       break;
     case TAB_MEDIA_STATE_NONE:
       NOTREACHED();
       break;
   }
   return result;
 }
 
+bool IsTabAudioMutingFeatureEnabled() {
+#if defined(USE_AURA)
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableTabAudioMuting);
+#else
+  return false;
+#endif
+}
+
+bool CanToggleAudioMute(content::WebContents* contents) {
+  switch (GetTabMediaStateForContents(contents)) {
+    case TAB_MEDIA_STATE_NONE:
+    case TAB_MEDIA_STATE_AUDIO_PLAYING:
+    case TAB_MEDIA_STATE_AUDIO_MUTING:
+      return IsTabAudioMutingFeatureEnabled();
+    case TAB_MEDIA_STATE_RECORDING:
+    case TAB_MEDIA_STATE_CAPTURING:
+      return false;
+  }
+  NOTREACHED();
+  return false;
+}
+
 }  // namespace chrome