Fixes a bug when the framebuffer is cleared with invalid scissor rect

cc/software_renderer.h

 // Copyright 2012 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 CC_SOFTWARE_RENDERER_H_
 #define CC_SOFTWARE_RENDERER_H_
 
 #include "base/basictypes.h"
 #include "cc/cc_export.h"
 #include "cc/direct_renderer.h"
@@ skipping 26 matching lines @@
 
     virtual void setVisible(bool) OVERRIDE;
 
     virtual void sendManagedMemoryStats(size_t bytesVisible, size_t bytesVisibleAndNearby, size_t bytesAllocated) OVERRIDE  { }
 
 protected:
     virtual void bindFramebufferToOutputSurface(DrawingFrame&) OVERRIDE;
     virtual bool bindFramebufferToTexture(DrawingFrame&, const ScopedResource*, const gfx::Rect& framebufferRect) OVERRIDE;
     virtual void setDrawViewportSize(const gfx::Size&) OVERRIDE;
     virtual void setScissorTestRect(const gfx::Rect& scissorRect) OVERRIDE;
-    virtual void clearFramebuffer(DrawingFrame&) OVERRIDE;
+    virtual void clearFramebuffer(DrawingFrame&, bool) OVERRIDE;
     virtual void drawQuad(DrawingFrame&, const DrawQuad*) OVERRIDE;
     virtual void beginDrawingFrame(DrawingFrame&) OVERRIDE;
     virtual void finishDrawingFrame(DrawingFrame&) OVERRIDE;
     virtual bool flippedFramebuffer() const OVERRIDE;
     virtual void ensureScissorTestEnabled() OVERRIDE;
     virtual void ensureScissorTestDisabled() OVERRIDE;
 
 private:
     SoftwareRenderer(RendererClient*, ResourceProvider*, SoftwareOutputDevice*);
 
@@ skipping 14 matching lines @@
     SkCanvas* m_skCurrentCanvas;
     SkPaint m_skCurrentPaint;
     scoped_ptr<ResourceProvider::ScopedWriteLockSoftware> m_currentFramebufferLock;
 
     DISALLOW_COPY_AND_ASSIGN(SoftwareRenderer);
 };
 
 }
 
 #endif  // CC_SOFTWARE_RENDERER_H_