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

chrome/browser/ui/cocoa/browser_window_cocoa.mm

Index: chrome/browser/ui/cocoa/browser_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index 46452efe9ee236de448f45c14b11d8be7d28efde..016a4ed862ba7252838c1a48e138fc30cd7e8a4e 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -249,16 +249,8 @@ void BrowserWindowCocoa::SetStarredState(bool is_starred) {
   [controller_ setStarredState:is_starred ? YES : NO];
 }
 
-void BrowserWindowCocoa::SetZoomIconState(ZoomController::ZoomIconState state) {
-  // TODO(khorimoto): Find someone to implement this.
-}
-
-void BrowserWindowCocoa::SetZoomIconTooltipPercent(int zoom_percent) {
-  // TODO(khorimoto): Find someone to implement this.
-}
-
-void BrowserWindowCocoa::ShowZoomBubble(int zoom_percent) {
-  // TODO(khorimoto): Find someone to implement this.
+void BrowserWindowCocoa::ZoomChangedForActiveTab(bool can_show_bubble) {
+  [controller_ zoomChangedForActiveTab:can_show_bubble ? YES : NO];
 }
 
 gfx::Rect BrowserWindowCocoa::GetRestoredBounds() const {