Added popup that shows the new Back shortcut on Mac.

chrome/browser/ui/cocoa/browser/exclusive_access_controller_views.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/browser/exclusive_access_controller_views.h"
 
 #include "chrome/browser/download/download_shelf.h"
 #include "chrome/browser/fullscreen.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/cocoa/accelerators_cocoa.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #import "chrome/browser/ui/cocoa/exclusive_access_bubble_window_controller.h"
 #include "chrome/browser/ui/exclusive_access/exclusive_access_manager.h"
 #include "chrome/browser/ui/status_bubble.h"
 #include "chrome/browser/ui/views/exclusive_access_bubble_views.h"
+#include "chrome/browser/ui/views/new_back_shortcut_bubble.h"
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_service.h"
 #include "ui/base/cocoa/cocoa_base_utils.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
 
 ExclusiveAccessController::ExclusiveAccessController(
     BrowserWindowController* controller,
     Browser* browser)
     : controller_(controller),
       browser_(browser),
@@ skipping 17 matching lines @@
   [cocoa_bubble_ closeImmediately];
   cocoa_bubble_.reset([[ExclusiveAccessBubbleWindowController alloc]
                  initWithOwner:controller_
       exclusive_access_manager:browser_->exclusive_access_manager()
                        profile:browser_->profile()
                            url:url_
                     bubbleType:bubble_type_]);
   [cocoa_bubble_ showWindow];
 }
 
+void ExclusiveAccessController::ShowNewBackShortcutBubble(bool forward) {
+  if (new_back_shortcut_bubble_)
+    new_back_shortcut_bubble_->UpdateContent(forward);
+  else
+    new_back_shortcut_bubble_.reset(new NewBackShortcutBubble(this, forward));
+}
+
 void ExclusiveAccessController::Destroy() {
   views_bubble_.reset();
   [cocoa_bubble_ closeImmediately];
   cocoa_bubble_.reset();
   url_ = GURL();
   bubble_type_ = EXCLUSIVE_ACCESS_BUBBLE_TYPE_NONE;
 }
 
 void ExclusiveAccessController::Layout(CGFloat max_y) {
   if (views_bubble_)
@@ skipping 120 matching lines @@
 }
 
 gfx::Rect ExclusiveAccessController::GetTopContainerBoundsInScreen() {
   NOTREACHED();  // Only used for ImmersiveMode.
   return gfx::Rect();
 }
 
 BrowserWindow* ExclusiveAccessController::GetBrowserWindow() const {
   return [controller_ browserWindow];
 }