Clean up error handling logic for extension tab muting

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"
@@ skipping 258 matching lines @@
 const std::string& GetTabAudioMutedCause(content::WebContents* contents) {
   LastMuteMetadata::CreateForWebContents(contents);  // Create if not exists.
   if (GetTabMediaStateForContents(contents) == TAB_MEDIA_STATE_CAPTURING) {
     // For tab capture, libcontent forces muting off.
     LastMuteMetadata::FromWebContents(contents)->cause =
         kMutedToggleCauseCapture;
   }
   return LastMuteMetadata::FromWebContents(contents)->cause;
 }
 
-void SetTabAudioMuted(content::WebContents* contents,
-                      bool mute,
-                      const std::string& cause) {
-  if (!contents || !chrome::CanToggleAudioMute(contents))
-    return;
+TabMutedResult SetTabAudioMuted(content::WebContents* contents,
+                                bool mute,
+                                const std::string& cause) {
+  DCHECK(contents);
+
+  if (!IsTabAudioMutingFeatureEnabled())
+    return TAB_MUTED_RESULT_FAIL_NOT_ENABLED;
+
+  if (!chrome::CanToggleAudioMute(contents))
+    return TAB_MUTED_RESULT_FAIL_TABCAPTURE;
 
   LastMuteMetadata::CreateForWebContents(contents);  // Create if not exists.
+
+  contents->SetAudioMuted(mute);
   LastMuteMetadata::FromWebContents(contents)->cause = cause;
 
-  contents->SetAudioMuted(mute);
+  return TAB_MUTED_RESULT_SUCCESS;
 }
 
 bool IsTabAudioMuted(content::WebContents* contents) {
   return contents && contents->IsAudioMuted();
 }
 
 bool AreAllTabsMuted(const TabStripModel& tab_strip,
                      const std::vector<int>& indices) {
   for (std::vector<int>::const_iterator i = indices.begin(); i != indices.end();
        ++i) {
     if (!IsTabAudioMuted(tab_strip.GetWebContentsAt(*i)))
       return false;
   }
   return true;
 }
 
 }  // namespace chrome