Flag and adapter class for software compositing.

content/renderer/gpu/compositor_output_surface.cc

Index: content/renderer/gpu/compositor_output_surface.cc
diff --git a/content/renderer/gpu/compositor_output_surface.cc b/content/renderer/gpu/compositor_output_surface.cc
index 1f1257ebd612ddc75dc02560bf43563d461d3f62..41da0d2a3568298fd1a6c0c73f97dccf0bea3d77 100644
--- a/content/renderer/gpu/compositor_output_surface.cc
+++ b/content/renderer/gpu/compositor_output_surface.cc
@@ -13,6 +13,7 @@
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 
 using WebKit::WebGraphicsContext3D;
+using WebKit::WebCompositorOutputCanvas2D;
 
 //------------------------------------------------------------------------------
 
@@ -28,12 +29,14 @@ IPC::ForwardingMessageFilter* CompositorOutputSurface::CreateFilter(
 
 CompositorOutputSurface::CompositorOutputSurface(
     int32 routing_id,
-    WebGraphicsContext3D* context3D)
+    WebGraphicsContext3D* context3D,
+    WebCompositorOutputCanvas2D* canvas2D)
     : output_surface_filter_(
           RenderThreadImpl::current()->compositor_output_surface_filter())
     , client_(NULL)
     , routing_id_(routing_id)
-    , context3D_(context3D) {
+    , context3D_(context3D)
+    , canvas2D_(canvas2D) {
   DCHECK(output_surface_filter_);
   capabilities_.hasParentCompositor = false;
   DetachFromThread();
@@ -56,8 +59,10 @@ bool CompositorOutputSurface::bindToClient(
     WebKit::WebCompositorOutputSurfaceClient* client) {
   DCHECK(CalledOnValidThread());
   DCHECK(!client_);
-  if (!context3D_->makeContextCurrent())
-    return false;
+  if (context3D_.get()) {
+    if (!context3D_->makeContextCurrent())
+      return false;
+  }
 
   client_ = client;
 
@@ -74,6 +79,10 @@ WebGraphicsContext3D* CompositorOutputSurface::context3D() const {
   return context3D_.get();
 }
 
+WebCompositorOutputCanvas2D* CompositorOutputSurface::canvas2D() {
+  return canvas2D_.get();
+}
+
 void CompositorOutputSurface::sendFrameToParentCompositor(
     const WebKit::WebCompositorFrame&) {
   DCHECK(CalledOnValidThread());