[Mac] Update tab audio icon to Material Design and tweak close box color.

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

 // Copyright 2013 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.
 
 #import "chrome/browser/ui/cocoa/tabs/alert_indicator_button_cocoa.h"
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
 #include "base/macros.h"
 #include "base/thread_task_runner_handle.h"
@@ skipping 54 matching lines @@
     [super setAction:@selector(handleClick:)];
   }
   return self;
 }
 
 - (void)removeFromSuperview {
   fadeAnimation_.reset();
   [super removeFromSuperview];
 }
 
+- (void)updateIconForState:(TabAlertState)aState {
+  if (aState != TabAlertState::NONE) {
+    TabView* const tabView = base::mac::ObjCCast<TabView>([self superview]);
+    SkColor iconColor = [tabView closeButtonColor];
+    NSImage* tabIndicatorImage =
+        chrome::GetTabAlertIndicatorImage(aState, iconColor).ToNSImage();
+    [self setImage:tabIndicatorImage];
+    affordanceImage_.reset([tabIndicatorImage retain]);

[Avi (use Gerrit), 2016/04/14 02:35:08]

You can do

affordanceImage_.reset(tabIndicatorImage, base::scoped_policy::RETAIN);

although now that I mention it, it's a bit longer.

+  }
+}
+
 - (void)transitionToAlertState:(TabAlertState)nextState {
   if (nextState == alertState_)
     return;
 
-  if (nextState != TabAlertState::NONE) {
-    [self
-        setImage:chrome::GetTabAlertIndicatorImage(nextState, 0).ToNSImage()];
-    affordanceImage_.reset(
-        [chrome::GetTabAlertIndicatorAffordanceImage(nextState, 0)
-                .ToNSImage() retain]);
-  }
+  [self updateIconForState:nextState];
 
   if ((alertState_ == TabAlertState::AUDIO_PLAYING &&
        nextState == TabAlertState::AUDIO_MUTING) ||
       (alertState_ == TabAlertState::AUDIO_MUTING &&
        nextState == TabAlertState::AUDIO_PLAYING) ||
       (alertState_ == TabAlertState::AUDIO_MUTING &&
        nextState == TabAlertState::NONE)) {
     // Instant user feedback: No fade animation.
     showingAlertState_ = nextState;
     fadeAnimation_.reset();
@@ skipping 134 matching lines @@
   TabView* const tabView = base::mac::ObjCCast<TabView>([self superview]);
   if (enable && tabView && ([tabView state] != NSOnState)) {
     const int requiredWidth =
         NSWidth([self frame]) * kMinMouseSelectableAreaPercent / 100;
     enable = ([tabView widthOfLargestSelectableRegion] >= requiredWidth);
   }
 
   [self setEnabled:enable];
 }
 
+// ThemedWindowDrawing protocol support.
+
+- (void)windowDidChangeTheme {
+  // Force the alert icon to update because the icon color may change based
+  // on the current theme.
+  [self updateIconForState:alertState_];
+}
+
+- (void)windowDidChangeActive {
+}
+
 @end