[Mac] Hide all shims when Chrome is hidden.

chrome/browser/app_controller_mac.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/app_controller_mac.h"
 
 #include "apps/app_shim/extension_app_shim_handler_mac.h"
 #include "apps/app_window_registry.h"
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 345 matching lines @@
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   [[[NSWorkspace sharedWorkspace] notificationCenter] removeObserver:self];
 }
 
 // (NSApplicationDelegate protocol) This is the Apple-approved place to override
 // the default handlers.
 - (void)applicationWillFinishLaunching:(NSNotification*)notification {
   // Nothing here right now.
 }
 
+- (void)applicationWillHide:(NSNotification*)notification {
+  apps::ExtensionAppShimHandler::OnChromeWillHide();
+}
+
 - (BOOL)tryToTerminateApplication:(NSApplication*)app {
   // Check for in-process downloads, and prompt the user if they really want
   // to quit (and thus cancel downloads). Only check if we're not already
   // shutting down, else the user might be prompted multiple times if the
   // download isn't stopped before terminate is called again.
   if (!browser_shutdown::IsTryingToQuit() &&
       ![self shouldQuitWithInProgressDownloads])
     return NO;
 
   // TODO(viettrungluu): Remove Apple Event handlers here? (It's safe to leave
@@ skipping 1161 matching lines @@
 
 //---------------------------------------------------------------------------
 
 namespace app_controller_mac {
 
 bool IsOpeningNewWindow() {
   return g_is_opening_new_window;
 }
 
 }  // namespace app_controller_mac