Fix keyboard focus for OOPIF-<webview>.

third_party/WebKit/public/web/WebView.h

 /*
  * Copyright (C) 2009, 2010, 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
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  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 183 matching lines @@
     // Focus ---------------------------------------------------------------
 
     virtual WebLocalFrame* focusedFrame() = 0;
     virtual void setFocusedFrame(WebFrame*) = 0;
 
     // Sets the provided frame as focused and fires blur/focus events on any
     // currently focused elements in old/new focused documents.  Note that this
     // is different from setFocusedFrame, which does not fire events on focused
     // elements.
     virtual void focusDocumentView(WebFrame*) = 0;
+    virtual void unfocusDocumentView(WebFrame*) = 0;

[dcheng, 2016/07/27 05:13:19]

Please add a comment and describe what the argument is supposed to be. I think I
would personally prefer that we just remove the argument or find another way to
express it... it's unused except for the DCHECK.

In this particular instance, I think the embedder can just express the DCHECK
directly by using WebView::focusedFrame?

 
     // Focus the first (last if reverse is true) focusable node.
     virtual void setInitialFocus(bool reverse) = 0;
 
     // Clears the focused element (and selection if a text field is focused)
     // to ensure that a text field on the page is not eating keystrokes we
     // send it.
     virtual void clearFocusedElement() = 0;
 
     // If it is editable, scrolls the element currently in focus into |rect|,
@@ skipping 313 matching lines @@
     // completed.
     WebWidget* widget() { return this; }
 
 protected:
     ~WebView() {}
 };
 
 } // namespace blink
 
 #endif