Update extension buttons to Material Design (Mac).

chrome/browser/ui/cocoa/toolbar/app_toolbar_button.mm

 // Copyright 2016 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/toolbar/app_toolbar_button.h"
 
 #include "base/macros.h"
 #import "chrome/browser/ui/cocoa/themed_window.h"
 #import "chrome/browser/ui/cocoa/view_id_util.h"
 
@@ skipping 30 matching lines @@
 - (void)awakeFromNib {
   [self commonInit];
 }
 
 - (void)commonInit {
   view_id_util::SetID(self, VIEW_ID_APP_MENU);
   delegate_.reset(new AppMenuButtonIconPainterDelegateMac(self));
   severity_ = AppMenuIconPainter::Severity::SEVERITY_NONE;
 }
 
-- (SkColor)iconColor:(BOOL)themeIsDark {
+- (gfx::VectorIconId)vectorIconId {
+  return gfx::VectorIconId::BROWSER_TOOLS;
+}
+
+- (SkColor)vectorIconColor:(BOOL)themeIsDark {
   const SkColor normalColor = SkColorSetRGB(0x5A, 0x5A, 0x5A);
   const SkColor normalIncognitoColor = SkColorSetRGB(0xFF, 0xFF, 0xFF);
   const SkColor severityMedColor = SkColorSetRGB(0xF0, 0x93, 0x00);
   const SkColor severityMedIncognitoColor = SkColorSetRGB(0xF7, 0xCB, 0x4D);
   const SkColor severityHighColor = SkColorSetRGB(0xC5, 0x39, 0x29);
   const SkColor severityHighIncognitoColor = SkColorSetRGB(0xE6, 0x73, 0x7C);
 
   switch (severity_) {
     case AppMenuIconPainter::Severity::SEVERITY_NONE:
     case AppMenuIconPainter::Severity::SEVERITY_LOW:
@@ skipping 10 matching lines @@
 
     default:
       break;
   }
 }
 
 - (void)setSeverity:(AppMenuIconPainter::Severity)severity
       shouldAnimate:(BOOL)shouldAnimate {
   if (severity != severity_) {
     severity_ = severity;
-    [self setImagesFromIconId:gfx::VectorIconId::BROWSER_TOOLS];
-    [self setNeedsDisplay:YES];
+    // Update the button state images with the new severity color.
+    [self resetButtonStateImages];
   }
 }
 
 @end