cc: Add mailbox support to ResourceProvider write locks.

cc/raster/one_copy_raster_buffer_provider.h

Index: cc/raster/one_copy_raster_buffer_provider.h
diff --git a/cc/raster/one_copy_raster_buffer_provider.h b/cc/raster/one_copy_raster_buffer_provider.h
index d30c3b59a6f8dc472305745898bcb8c32163630a..07f8a0d3ce2d6e311e6705c90590d5be54b0bf27 100644
--- a/cc/raster/one_copy_raster_buffer_provider.h
+++ b/cc/raster/one_copy_raster_buffer_provider.h
@@ -12,6 +12,7 @@
 #include "cc/raster/raster_buffer_provider.h"
 #include "cc/raster/staging_buffer_pool.h"
 #include "cc/resources/resource_provider.h"
+#include "gpu/command_buffer/common/sync_token.h"
 
 namespace cc {
 struct StagingBuffer;
@@ -27,7 +28,8 @@ class CC_EXPORT OneCopyRasterBufferProvider : public RasterBufferProvider {
                               int max_copy_texture_chromium_size,
                               bool use_partial_raster,
                               int max_staging_buffer_usage_in_bytes,
-                              ResourceFormat preferred_tile_format);
+                              ResourceFormat preferred_tile_format,
+                              bool async_worker_context_enabled);
   ~OneCopyRasterBufferProvider() override;
 
   // Overridden from RasterBufferProvider:
@@ -65,7 +67,6 @@ class CC_EXPORT OneCopyRasterBufferProvider : public RasterBufferProvider {
       uint64_t previous_content_id,
       uint64_t new_content_id);
   void CopyOnWorkerThread(StagingBuffer* staging_buffer,
-                          const Resource* resource,
                           ResourceProvider::ScopedWriteLockGL* resource_lock,
                           const RasterSource* raster_source,
                           uint64_t previous_content_id,
@@ -83,6 +84,9 @@ class CC_EXPORT OneCopyRasterBufferProvider : public RasterBufferProvider {
   ResourceFormat preferred_tile_format_;
   StagingBufferPool staging_pool_;
 
+  bool async_worker_context_enabled_;
+  gpu::SyncToken sync_token_;
+
   DISALLOW_COPY_AND_ASSIGN(OneCopyRasterBufferProvider);
 };