gpu: Refactor GpuMemoryBuffer framework for multi-process support.

cc/resources/raster_worker_pool.h

Index: cc/resources/raster_worker_pool.h
diff --git a/cc/resources/raster_worker_pool.h b/cc/resources/raster_worker_pool.h
index d0e1e7c0de0a14f070ed9f9347a919f42831e283..8c4b4934c56e6a1fecd59b2de4d4210387ed303d 100644
--- a/cc/resources/raster_worker_pool.h
+++ b/cc/resources/raster_worker_pool.h
@@ -13,6 +13,7 @@
 #include "cc/resources/raster_mode.h"
 #include "cc/resources/tile_priority.h"
 #include "cc/resources/worker_pool.h"
+#include "third_party/khronos/GLES2/gl2.h"
 
 class SkDevice;
 
@@ -183,6 +184,9 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
   // even if they later get canceled by another call to ScheduleTasks().
   virtual void ScheduleTasks(RasterTask::Queue* queue) = 0;
 
+  // Returns the format that needs to be used for raster task resources.
+  virtual GLenum GetResourceFormat() const = 0;
+
   // TODO(vmpstr): Figure out an elegant way to not pass this many parameters.
   static RasterTask CreateRasterTask(
       const Resource* resource,