Make all methods on WebLayerTreeView optional.

Source/web/tests/WebFrameTest.cpp

 /*
  * 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 4509 matching lines @@
     EXPECT_EQ(startRect, initialStartRect);
     EXPECT_EQ(endRect, initialEndRect);
 }
 #endif
 
 class CompositedSelectionBoundsTestLayerTreeView : public WebLayerTreeView {
 public:
     CompositedSelectionBoundsTestLayerTreeView() : m_selectionCleared(false) { }
     ~CompositedSelectionBoundsTestLayerTreeView() override { }
 
-    void setRootLayer(const WebLayer&)  override { }

[pdr., 2015/08/19 23:46:01]

Can't you just copy this code in your test? I like pure virtual (or, almost
pure) because it prevents mistakes in real subclasses.

-    void clearRootLayer()  override { }
-    void setViewportSize(const WebSize& deviceViewportSize)  override { }
-    WebSize deviceViewportSize() const  override { return WebSize(); }
-    void setDeviceScaleFactor(float) override { }
-    float deviceScaleFactor() const  override { return 1.f; }
-    void setBackgroundColor(WebColor)  override { }
-    void setHasTransparentBackground(bool)  override { }
-    void setVisible(bool)  override { }
-    void setPageScaleFactorAndLimits(float pageScaleFactor, float minimum, float maximum)  override { }
-    void startPageScaleAnimation(const WebPoint& destination, bool useAnchor, float newPageScale, double durationSec)  override { }
-    void finishAllRendering()  override { }
     void registerSelection(const WebSelection& selection) override
     {
         m_selection = adoptPtr(new WebSelection(selection));
     }
+
     void clearSelection() override
     {
         m_selectionCleared = true;
         m_selection.clear();
     }
 
     bool getAndResetSelectionCleared()
     {
         bool selectionCleared  = m_selectionCleared;
         m_selectionCleared = false;
@@ skipping 3485 matching lines @@
 
 TEST_F(WebFrameTest, MaxFramesDetach)
 {
     registerMockedHttpURLLoad("max-frames-detach.html");
     FrameTestHelpers::WebViewHelper webViewHelper;
     WebViewImpl* webViewImpl = webViewHelper.initializeAndLoad(m_baseURL + "max-frames-detach.html", true);
     webViewImpl->mainFrameImpl()->collectGarbage();
 }
 
 } // namespace blink