[devtools] Allow transparent base background color overrides.

third_party/WebKit/Source/web/WebViewImpl.h

 /*
  * Copyright (C) 2010 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 268 matching lines @@
   float minimumPageScaleFactor() const;
   float maximumPageScaleFactor() const;
   float clampPageScaleFactorToLimits(float) const;
   void resetScaleStateImmediately();
 
   HitTestResult coreHitTestResultAt(const WebPoint&);
   void invalidateRect(const IntRect&);
 
   void setBaseBackgroundColor(WebColor);
   void setBaseBackgroundColorOverride(WebColor);
+  void clearBaseBackgroundColorOverride();
   void setBackgroundColorOverride(WebColor);
   void setZoomFactorOverride(float);
   void setCompositorDeviceScaleFactorOverride(float);
   void setDeviceEmulationTransform(const TransformationMatrix&);
   TransformationMatrix getDeviceEmulationTransformForTesting() const;
 
   Color baseBackgroundColor() const;
   WebColor backgroundColorOverride() const { return m_backgroundColorOverride; }
 
   Frame* focusedCoreFrame() const;
@@ skipping 400 matching lines @@
   std::unique_ptr<WebActiveGestureAnimation> m_gestureAnimation;
   WebPoint m_positionOnFlingStart;
   WebPoint m_globalPositionOnFlingStart;
   int m_flingModifier;
   WebGestureDevice m_flingSourceDevice;
   Vector<std::unique_ptr<LinkHighlightImpl>> m_linkHighlights;
   std::unique_ptr<CompositorAnimationTimeline> m_linkHighlightsTimeline;
   std::unique_ptr<FullscreenController> m_fullscreenController;
 
   WebColor m_baseBackgroundColor;
+  bool m_baseBackgroundColorOverrideEnabled;
   WebColor m_baseBackgroundColorOverride;
   WebColor m_backgroundColorOverride;
   float m_zoomFactorOverride;
 
   bool m_userGestureObserved;
   bool m_shouldDispatchFirstVisuallyNonEmptyLayout;
   bool m_shouldDispatchFirstLayoutAfterFinishedParsing;
   bool m_shouldDispatchFirstLayoutAfterFinishedLoading;
   WebDisplayMode m_displayMode;
 
@@ skipping 21 matching lines @@
   Persistent<ResizeViewportAnchor> m_resizeViewportAnchor;
 };
 
 // We have no ways to check if the specified WebView is an instance of
 // WebViewImpl because WebViewImpl is the only implementation of WebView.
 DEFINE_TYPE_CASTS(WebViewImpl, WebView, webView, true, true);
 
 }  // namespace blink
 
 #endif