cc: Route offscreen context creation for compositor to the browser.

content/browser/renderer_host/compositor_impl_android.cc

Index: content/browser/renderer_host/compositor_impl_android.cc
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index 7954175feea775ff47621cde2141af9af49b1bd5..3645cd045439be49934d898074c406ed0863080c 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -28,6 +28,7 @@
 #include "third_party/khronos/GLES2/gl2ext.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 #include "ui/gfx/android/java_bitmap.h"
+#include "ui/gl/context_provider.h"
 #include "webkit/glue/webthread_impl.h"
 #include "webkit/gpu/webgraphicscontext3d_in_process_impl.h"
 
@@ -326,6 +327,31 @@ void CompositorImpl::scheduleComposite() {
   client_->ScheduleComposite();
 }
 
+class NullContextProvider : public ui::ContextProvider {
+  // TODO(danakj): Get a context through ImageTransportSurfaceAndroid.
+  virtual bool InitializeOnMainThread() { return false; }
+  virtual bool BindToCurrentThread() { return false; }
+  virtual WebKit::WebGraphicsContext3D* Context3d() { return NULL; }
+  virtual class GrContext* GrContext() { return NULL; }
+  virtual void VerifyContexts() {}
+ protected:
+  virtual ~NullContextProvider() {}
+};
+
+scoped_refptr<ui::ContextProvider>
+CompositorImpl::OffscreenContextProviderForMainThread() {
+  if (!null_offscreen_context_provider_)
+    null_offscreen_context_provider_ = new NullContextProvider();
+  return null_offscreen_context_provider_;
+}
+
+scoped_refptr<ui::ContextProvider>
+CompositorImpl::OffscreenContextProviderForCompositorThread() {
+  if (!null_offscreen_context_provider_)
+    null_offscreen_context_provider_ = new NullContextProvider();
+  return null_offscreen_context_provider_;

[piman, 2013/02/21 22:49:48]

I assume that Android UI doesn't use filters right now?

[danakj, 2013/02/22 01:56:31]

Right. And don't intend to use filters that will require this context. I
confirmed this with @aelias.

[piman, 2013/02/22 02:54:07]

Worth a comment? "If you're trying to use filters and the world blows up,
implement this..."

[danakj, 2013/02/22 03:04:49]

ya, sure! the world won't blow cuz we nullcheck them, but it'll do nothing.

+}
+
 void CompositorImpl::OnViewContextSwapBuffersPosted() {
   TRACE_EVENT0("compositor", "CompositorImpl::OnViewContextSwapBuffersPosted");
 }