Correctly sets the security origin for the IME window.

chrome/browser/ui/ime/ime_window.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_IME_IME_WINDOW_H_
 #define CHROME_BROWSER_UI_IME_IME_WINDOW_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "extensions/browser/extension_icon_image.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/image/image.h"
 #include "ui/views/widget/widget_delegate.h"
 #include "ui/views/widget/widget_observer.h"
 
 class GURL;
 class Profile;
 
 namespace content {
+class RenderFrameHost;
 class WebContents;
 }
 
 namespace extensions {
 class Extension;
 }
 
 namespace gfx {
 class Image;
 class Rect;
@@ skipping 17 matching lines @@
                   public extensions::IconImage::Observer,
                   public content::WebContentsDelegate {
  public:
   enum Mode { NORMAL, FOLLOW_CURSOR };
 
   // Takes |url| as string instead of GURL because resolving GURL requires
   // |extension|. As the client code already passes in |extension|, it'd be
   // better to simply the client code.
   ImeWindow(Profile* profile,
             const extensions::Extension* extension,
+            content::RenderFrameHost* render_frame_host,

[Devlin, 2016/03/02 18:05:11]

Document |render_frame_host| - and maybe even rename it to
opener_render_frame_host or something.

[Shu Chen, 2016/03/03 01:33:32]

Done.

             const std::string& url,
             Mode mode,
             const gfx::Rect& bounds);
 
   // Methods delegate to ImeNativeWindow.
   void Show();
   void Hide();
   void Close();
   void SetBounds(const gfx::Rect& bounds);
   // Aligns the follow-cursor window to the given cursor bounds.
@@ skipping 63 matching lines @@
   ImeNativeWindow* native_window_;  // Weak, it does self-destruction.
 
   base::ObserverList<ImeWindowObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(ImeWindow);
 };
 
 }  // namespace ui
 
 #endif  // CHROME_BROWSER_UI_IME_IME_WINDOW_H_