Mac: Audio indicator in each tab

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

Index: chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
index 1f0c0cb3d3837ea482460b741bb2eef400cc5e93..17c28f8094acac4689326f1d81ae9868e742dab9 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
@@ -111,6 +111,9 @@ const CGFloat kProjectingIconWidthAndHeight = 32.0;
 // Throbbing duration on webrtc "this web page is watching you" favicon overlay.
 const int kRecordingDurationMs = 1000;
 
+// Throbbing duration on audio playing animation.
+const int kAudioPlayingDurationMs = 2000;
+
 // Helper class for doing NSAnimationContext calls that takes a bool to disable
 // all the work.  Useful for code that wants to conditionally animate.
 class ScopedNSAnimationContextGroup {
@@ -1604,6 +1607,20 @@ NSImage* Overlay(NSImage* ground, NSImage* overlay, CGFloat alpha) {
                   autorelease];
 
           iconView = recordingView;
+        } else if (theme && chrome::IsPlayingAudio(contents)) {
+          NSImage* audioImage =
+              theme->GetNSImageNamed(IDR_AUDIO_ANIMATION, true);
+          NSRect frame =
+              NSMakeRect(0, 0, kIconWidthAndHeight, kIconWidthAndHeight);
+          ThrobbingImageView* equalizerFaviconView =
+              [[[ThrobbingImageView alloc]
+                  initWithFrame:frame
+                backgroundImage:[imageView image]
+                     throbImage:audioImage
+                     durationMS:kAudioPlayingDurationMs] autorelease];
+          [equalizerFaviconView setTweenType:ui::Tween::LINEAR];
+
+          iconView = equalizerFaviconView;
         } else {
           iconView = imageView;
         }