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

cc/direct_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_DIRECT_RENDERER_H_
 #define CC_DIRECT_RENDERER_H_
 
 #include "base/basictypes.h"
 #include "cc/cc_export.h"
 #include "cc/renderer.h"
@@ skipping 40 matching lines @@
     class CachedResource : public ScopedResource {
     public:
         static scoped_ptr<CachedResource> create(ResourceProvider* resourceProvider) {
           return make_scoped_ptr(new CachedResource(resourceProvider));
         }
         virtual ~CachedResource() {}
 
         bool isComplete() const { return m_isComplete; }
         void setIsComplete(bool isComplete) { m_isComplete = isComplete; }
 
+        bool needsFullClear() const { return m_needsFullClear; }
+        void setNeedsFullClear(bool fullClear) { m_needsFullClear = fullClear; }
+
     protected:
         explicit CachedResource(ResourceProvider* resourceProvider)
             : ScopedResource(resourceProvider)
             , m_isComplete(false)
+            , m_needsFullClear(false)
         {
         }
 
     private:
         bool m_isComplete;
+        bool m_needsFullClear;
 
         DISALLOW_COPY_AND_ASSIGN(CachedResource);
     };
 
     static gfx::RectF quadVertexRect();
     static void quadRectTransform(gfx::Transform* quadRectTransform, const gfx::Transform& quadTransform, const gfx::RectF& quadRect);
     static void initializeMatrices(DrawingFrame&, const gfx::Rect& drawRect, bool flipY);
     static gfx::Rect moveScissorToWindowSpace(const DrawingFrame&, gfx::RectF scissorRect);
     static gfx::RectF computeScissorRectForRenderPass(const DrawingFrame& frame);
     void setScissorStateForQuad(const DrawingFrame& frame, const DrawQuad& quad);
     void setScissorStateForQuadWithRenderPassScissor(const DrawingFrame& frame, const DrawQuad& quad, const gfx::RectF& renderPassScissor, bool* shouldSkipQuad);
 
     bool haveCachedResources(RenderPass::Id) const;
     static gfx::Size renderPassTextureSize(const RenderPass*);
     static GLenum renderPassTextureFormat(const RenderPass*);
 
     void drawRenderPass(DrawingFrame&, const RenderPass*);
     bool useRenderPass(DrawingFrame&, const RenderPass*);
 
     virtual void bindFramebufferToOutputSurface(DrawingFrame&) = 0;
     virtual bool bindFramebufferToTexture(DrawingFrame&, const ScopedResource*, const gfx::Rect& framebufferRect) = 0;
     virtual void setDrawViewportSize(const gfx::Size&) = 0;
     virtual void setScissorTestRect(const gfx::Rect& scissorRect) = 0;
-    virtual void clearFramebuffer(DrawingFrame&) = 0;
+    virtual void clearFramebuffer(DrawingFrame&, bool) = 0;
     virtual void drawQuad(DrawingFrame&, const DrawQuad*) = 0;
     virtual void beginDrawingFrame(DrawingFrame&) = 0;
     virtual void finishDrawingFrame(DrawingFrame&) = 0;
     virtual void finishDrawingQuadList();
     virtual bool flippedFramebuffer() const = 0;
     virtual void ensureScissorTestEnabled() = 0;
     virtual void ensureScissorTestDisabled() = 0;
 
     ScopedPtrHashMap<RenderPass::Id, CachedResource> m_renderPassTextures;
     ResourceProvider* m_resourceProvider;
 
 private:
 
     gfx::Vector2d m_enlargePassTextureAmount;
 
     DISALLOW_COPY_AND_ASSIGN(DirectRenderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_DIRECT_RENDERER_H_