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 d95c33cc4f60b01826c6a8809c6c87a0d48e7fdd..6e09b8fd6a58f1ffb541a284b23b00bfa2b380d2 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -249,16 +249,10 @@ 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) {
+  // TODO(dbeam): make sure a truthy |can_show_bubble| is only sent to the
+  // location bar when the wrench menu is hidden.
+  [controller_ zoomChangedForActiveTab:can_show_bubble ? YES : NO];
 }
 
 gfx::Rect BrowserWindowCocoa::GetRestoredBounds() const {