Clean up error handling logic for extension tab muting

chrome/browser/ui/tabs/tab_utils.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_TABS_TAB_UTILS_H_
 #define CHROME_BROWSER_UI_TABS_TAB_UTILS_H_
 
 #include <string>
 #include <vector>
-
+#include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "content/public/browser/web_contents_user_data.h"
 
 class TabStripModel;
 
 namespace content {
 class WebContents;
 }  // namespace content
 
 namespace gfx {
 class Animation;
 class Image;
 }  // namespace gfx
 
 // Media state for a tab.  In reality, more than one of these may apply.  See
 // comments for GetTabMediaStateForContents() below.
 enum TabMediaState {
   TAB_MEDIA_STATE_NONE,
   TAB_MEDIA_STATE_RECORDING,  // Audio/Video being recorded, consumed by tab.
   TAB_MEDIA_STATE_CAPTURING,  // Tab contents being captured.
   TAB_MEDIA_STATE_AUDIO_PLAYING,  // Audible audio is playing from the tab.
   TAB_MEDIA_STATE_AUDIO_MUTING,  // Tab audio is being muted.
 };
 
+enum TabMutedResult {
+  TAB_MUTED_RESULT_SUCCESS,
+  TAB_MUTED_RESULT_FAIL_NOT_ENABLED,
+  TAB_MUTED_RESULT_FAIL_TABCAPTURE,
+  TAB_MUTED_RESULT_FAIL_RATE_LIMITED,
+};
+
 namespace chrome {
 
 // String to indicate reason for muted state change (user, capture, extension
 // id, or empty string)
 extern const char kMutedToggleCauseUser[];
 extern const char kMutedToggleCauseCapture[];
 
+// Constants for rate limiting mute updating by extensions
+extern const int kMuteTokenBucketCostSeconds;

[miu, 2015/07/18 00:42:42]

Just noticed this: Since these two constants are used only inside tab_utils.cc,
you don't need to declare them in the header file.  So, please delete these two
from this header file.

[Jared Sohn, 2015/07/18 23:57:24]

When this is done, I get an error message that says that the
kMuteTokenBucketCapacitySeconds variable used in the constructor for
LastMuteMetadata is undefined.  It will compile correctly if I define the
constants in the file prior to the struct, but now these variables are in the
global namespace but not externed.  Is this okay?

On 2015/07/18 at 00:42:42, miu wrote:

+extern const int kMuteTokenBucketCapacitySeconds;
+
 // Logic to determine which components (i.e., close button, favicon, and media
 // indicator) of a tab should be shown, given current state.  |capacity|
 // specifies how many components can be shown, given available tab width.
 //
 // Precedence rules for deciding what to show when capacity is insufficient to
 // show everything:
 //
 //   Active tab: Always show the close button, then the media indicator, then
 //               the favicon.
 //   Inactive tab: Media indicator, then the favicon, then the close button.
@@ skipping 49 matching lines @@
 
 // Returns true if audio mute can be activated/deactivated for the given
 // |contents|.
 bool CanToggleAudioMute(content::WebContents* contents);
 
 // Indicates whether all audio output from |contents| is muted.
 bool IsTabAudioMuted(content::WebContents* contents);
 
 // Sets whether all audio output from |contents| is muted.
 // Cause is extensionid, kMutedToggleCause constant, or empty string
-void SetTabAudioMuted(content::WebContents* contents,
-                      bool mute,
-                      const std::string& cause);
+TabMutedResult SetTabAudioMuted(content::WebContents* contents,
+                                bool mute,
+                                const std::string& cause);
 
 // Get cause of mute (extensionid, kMutedToggleCause constant, or empty string)
 const std::string& GetTabAudioMutedCause(content::WebContents* contents);
 
 // Returns true if the tabs at the |indices| in |tab_strip| are all muted.
 bool AreAllTabsMuted(const TabStripModel& tab_strip,
                      const std::vector<int>& indices);
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_TABS_TAB_UTILS_H_