Refactor browser window zoom handling and enable zoom icon on all platforms.

chrome/browser/ui/cocoa/browser_window_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 
 #include <cmath>
 #include <numeric>
 
 #include "base/command_line.h"
@@ skipping 1167 matching lines @@
 - (void)updateToolbarWithContents:(WebContents*)tab
                shouldRestoreState:(BOOL)shouldRestore {
   [toolbarController_ updateToolbarWithContents:tab
                              shouldRestoreState:shouldRestore];
 }
 
 - (void)setStarredState:(BOOL)isStarred {
   [toolbarController_ setStarredState:isStarred];
 }
 
+- (void)zoomChangedForActiveTab:(BOOL)canShowBubble {
+  [toolbarController_ zoomChangedForActiveTab:canShowBubble];
+}
+
 // Return the rect, in WebKit coordinates (flipped), of the window's grow box
 // in the coordinate system of the content area of the currently selected tab.
 // |windowGrowBox| needs to be in the window's coordinate system.
 - (NSRect)selectedTabGrowBoxRect {
   NSWindow* window = [self window];
   if (![window respondsToSelector:@selector(_growBoxRect)])
     return NSZeroRect;
 
   // Before we return a rect, we need to convert it from window coordinates
   // to tab content area coordinates and flip the coordinate system.
@@ skipping 1003 matching lines @@
 
 - (BOOL)supportsBookmarkBar {
   return [self supportsWindowFeature:Browser::FEATURE_BOOKMARKBAR];
 }
 
 - (BOOL)isTabbedWindow {
   return browser_->is_type_tabbed();
 }
 
 @end  // @implementation BrowserWindowController(WindowType)