Implement transform/clip support for Android WebView.

cc/output/direct_renderer.h

Index: cc/output/direct_renderer.h
diff --git a/cc/output/direct_renderer.h b/cc/output/direct_renderer.h
index 7c37551f299ba20dc00359c8788660672df2c9f7..e2bf7c74f4ab54805f84a6dd873cd6c0f3886c67 100644
--- a/cc/output/direct_renderer.h
+++ b/cc/output/direct_renderer.h
@@ -79,10 +79,11 @@ class CC_EXPORT DirectRenderer : public Renderer {
                                 const gfx::Transform& quad_transform,
                                 const gfx::RectF& quad_rect);
   static void InitializeMatrices(DrawingFrame* frame,
+                                 gfx::Vector2d offset,
                                  gfx::Rect draw_rect,
                                  bool flip_y);
-  static gfx::Rect MoveScissorToWindowSpace(const DrawingFrame* frame,
-                                            const gfx::RectF& scissor_rect);
+  gfx::Rect MoveScissorToWindowSpace(const DrawingFrame* frame,
+                                     const gfx::RectF& scissor_rect);
   static gfx::RectF ComputeScissorRectForRenderPass(const DrawingFrame* frame);
   void SetScissorStateForQuad(const DrawingFrame* frame, const DrawQuad& quad);
   void SetScissorStateForQuadWithRenderPassScissor(
@@ -101,7 +102,7 @@ class CC_EXPORT DirectRenderer : public Renderer {
   virtual bool BindFramebufferToTexture(DrawingFrame* frame,
                                         const ScopedResource* resource,
                                         gfx::Rect framebuffer_rect) = 0;
-  virtual void SetDrawViewportSize(gfx::Size viewport_size) = 0;
+  virtual void SetDrawViewport(gfx::Rect viewport) = 0;
   virtual void SetScissorTestRect(gfx::Rect scissor_rect) = 0;
   virtual void ClearFramebuffer(DrawingFrame* frame) = 0;
   virtual void DoDrawQuad(DrawingFrame* frame, const DrawQuad* quad) = 0;