Replace PlaceholderFrameOwner with RemoteBridgeFrameOwner.

public/web/WebRemoteFrame.h

 // Copyright 2014 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 WebRemoteFrame_h
 #define WebRemoteFrame_h
 
 #include "public/web/WebFrame.h"
 #include "public/web/WebSandboxFlags.h"
 
 namespace blink {
 
 class WebFrameClient;
 class WebRemoteFrameClient;
 
 class WebRemoteFrame : public WebFrame {
 public:
     BLINK_EXPORT static WebRemoteFrame* create(WebRemoteFrameClient*);
 
     virtual WebLocalFrame* createLocalChild(const WebString& name, WebSandboxFlags, WebFrameClient*) = 0;
+
+    // FIXME(alexmos): remove once Chrome side is updated to use sandbox flags.
     virtual WebRemoteFrame* createRemoteChild(const WebString& name, WebRemoteFrameClient*) = 0;
+    virtual WebRemoteFrame* createRemoteChild(const WebString& name, WebSandboxFlags, WebRemoteFrameClient*) = 0;
 
     // Transfer initial drawing parameters from a local frame.
     virtual void initializeFromFrame(WebLocalFrame*) const = 0;
 
     // Set security origin replicated from another process.
     virtual void setReplicatedOrigin(const WebSecurityOrigin&) const = 0;
 
     // Set sandbox flags replicated from another process.
     virtual void setReplicatedSandboxFlags(WebSandboxFlags) const = 0;
 
     // Set frame name replicated from another process.
     virtual void setReplicatedName(const WebString&) const = 0;
 
     virtual void didStartLoading() = 0;
     virtual void didStopLoading() = 0;
 };
 
 } // namespace blink
 
 #endif // WebRemoteFrame_h