Implemented new fence syncs which replaces the old sync points.

gpu/command_buffer/common/gles2_cmd_format.h

Index: gpu/command_buffer/common/gles2_cmd_format.h
diff --git a/gpu/command_buffer/common/gles2_cmd_format.h b/gpu/command_buffer/common/gles2_cmd_format.h
index d1ad74005c58d78e79b052dc104c90f67abef39e..d2d5319a4c73b1a08c4472654d8d73a12a70c335 100644
--- a/gpu/command_buffer/common/gles2_cmd_format.h
+++ b/gpu/command_buffer/common/gles2_cmd_format.h
@@ -201,6 +201,13 @@ struct UniformsES3Header {
   // UniformES3Info uniforms[num_uniforms];
 };
 
+// The format of fence sync tokens.
+struct SyncToken {
+  int channel_client_id;
+  uint32_t route_id;
+  uint32_t release_count;
+};
+
 // The format of QuerySync used by EXT_occlusion_query_boolean
 struct QuerySync {
   void Reset() {