Instant: Use only one hidden WebContents per profile.

chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h

+// Copyright 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.
+
+#ifndef CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_OVERLAY_CONTROLLER_MAC_H_
+#define CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_OVERLAY_CONTROLLER_MAC_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/instant/instant_overlay_controller.h"
+
+class Browser;
+@class BrowserWindowController;
+@class OverlayableContentsController;
+
+class InstantOverlayControllerMac : public InstantOverlayController {
+ public:
+  InstantOverlayControllerMac(Browser* browser,
+                              BrowserWindowController* window,
+                              OverlayableContentsController* overlay);
+  virtual ~InstantOverlayControllerMac();
+
+ private:
+  // Overridden from InstantOverlayController:
+  virtual void OverlayStateChanged(const InstantModel& model) OVERRIDE;
+
+  BrowserWindowController* const window_;
+  OverlayableContentsController* const overlay_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstantOverlayControllerMac);
+};
+
+#endif  // CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_OVERLAY_CONTROLLER_MAC_H_