WIP GPU scheduler + delayed activation / tile draw

cc/raster/gpu_raster_buffer_provider.h

Index: cc/raster/gpu_raster_buffer_provider.h
diff --git a/cc/raster/gpu_raster_buffer_provider.h b/cc/raster/gpu_raster_buffer_provider.h
index 7c674d37f9d9c5c7b80b90f556007e563d85de15..02a8ee6c7f252d2f0e71afc133226c9fc7a8b20c 100644
--- a/cc/raster/gpu_raster_buffer_provider.h
+++ b/cc/raster/gpu_raster_buffer_provider.h
@@ -7,6 +7,7 @@
 
 #include <stdint.h>
 
+#include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "cc/raster/raster_buffer_provider.h"
 #include "cc/resources/resource_provider.h"
@@ -32,6 +33,9 @@ class CC_EXPORT GpuRasterBufferProvider : public RasterBufferProvider {
       uint64_t previous_content_id) override;
   void ReleaseBufferForRaster(std::unique_ptr<RasterBuffer> buffer) override;
   void OrderingBarrier() override;
+  bool IsResourceReadyToDraw(const Resource* resource) override;
+  void SignalResourcesReadyToDraw(const std::vector<const Resource*>& resources,
+                                  const base::Closure& callback) override;
   ResourceFormat GetResourceFormat(bool must_support_alpha) const override;
   bool IsResourceSwizzleRequired(bool must_support_alpha) const override;
   bool CanPartialRasterIntoProvidedResource() const override;
@@ -54,7 +58,6 @@ class CC_EXPORT GpuRasterBufferProvider : public RasterBufferProvider {
     RasterBufferImpl(GpuRasterBufferProvider* client,
                      ResourceProvider* resource_provider,
                      ResourceId resource_id,
-                     bool async_worker_context_enabled,
                      bool resource_has_previous_content);
     ~RasterBufferImpl() override;