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

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

Index: chrome/browser/ui/cocoa/tabs/alert_indicator_button_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/tabs/alert_indicator_button_cocoa.mm b/chrome/browser/ui/cocoa/tabs/alert_indicator_button_cocoa.mm
index 7bfde635e58cbed315e936a7a0c1051b95215500..0bfe358743f9352742b0dcf61d37c33d08875ae5 100644
--- a/chrome/browser/ui/cocoa/tabs/alert_indicator_button_cocoa.mm
+++ b/chrome/browser/ui/cocoa/tabs/alert_indicator_button_cocoa.mm
@@ -72,17 +72,22 @@ class FadeAnimationDelegate : public gfx::AnimationDelegate {
   [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) ||
@@ -237,4 +242,15 @@ class FadeAnimationDelegate : public gfx::AnimationDelegate {
   [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