Reland of Use full viewport height for layout if URL bar is locked shown or hidden.

third_party/WebKit/Source/core/frame/BrowserControls.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 BrowserControls_h
 #define BrowserControls_h
 
 #include "core/CoreExport.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebBrowserControlsState.h"
@@ skipping 31 matching lines @@
   void updateConstraintsAndState(WebBrowserControlsState constraints,
                                  WebBrowserControlsState current,
                                  bool animate);
 
   void scrollBegin();
 
   // Scrolls browser controls vertically if possible and returns the remaining
   // scroll amount.
   FloatSize scrollBy(FloatSize scrollDelta);
 
+  WebBrowserControlsState permittedState() const { return m_permittedState; }
+
  private:
   explicit BrowserControls(const FrameHost&);
   void resetBaseline();
 
   Member<const FrameHost> m_frameHost;
 
   // The browser controls height regardless of whether it is visible or not.
   float m_height;
 
   // The browser controls shown amount (normalized from 0 to 1) since the last
@@ skipping 15 matching lines @@
   // If this is true, then the embedder shrunk the WebView size by the top
   // controls height.
   bool m_shrinkViewport;
 
   // Constraints on the browser controls state
   WebBrowserControlsState m_permittedState;
 };
 }  // namespace blink
 
 #endif  // BrowserControls_h