Implement transform/clip support for Android WebView.

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index 15766c4ef0dba0b4b68870090d4f1e286e646f15..c2acb7668447a6fdded2f4fec29af8cde467b741 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -2374,8 +2374,8 @@ bool GLRenderer::BindFramebufferToTexture(DrawingFrame* frame,
   DCHECK(context_->checkFramebufferStatus(GL_FRAMEBUFFER) ==
          GL_FRAMEBUFFER_COMPLETE || IsContextLost());
 
-  InitializeMatrices(frame, framebuffer_rect, false);
-  SetDrawViewportSize(framebuffer_rect.size());
+  InitializeMatrices(frame, gfx::Vector2d(), framebuffer_rect, false);
+  SetDrawViewport(gfx::Rect(framebuffer_rect.size()));
 
   return true;
 }
@@ -2397,10 +2397,12 @@ void GLRenderer::SetScissorTestRect(gfx::Rect scissor_rect) {
                         scissor_rect.height()));
 }
 
-void GLRenderer::SetDrawViewportSize(gfx::Size viewport_size) {
-  current_framebuffer_size_ = viewport_size;
-  GLC(context_,
-      context_->viewport(0, 0, viewport_size.width(), viewport_size.height()));
+void GLRenderer::SetDrawViewport(gfx::Rect viewport) {
+  current_framebuffer_size_ = viewport.size();
+  GLC(context_, context_->viewport(viewport.x(),
+                                   viewport.y(),
+                                   viewport.width(),
+                                   viewport.height()));
 }
 
 bool GLRenderer::MakeContextCurrent() { return context_->makeContextCurrent(); }