gpu: Allow waiting on sync tokens without sync token client.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h

Index: gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
index 0193b4aa35b665c8ab5f2415686367ec3f2ea813..cd7ef379cddcc1da0e093ac7e101fddd61c3aa1f 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
@@ -12,6 +12,7 @@
 #include "gpu/command_buffer/common/gles2_cmd_format.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "gpu/command_buffer/common/mailbox.h"
+#include "gpu/command_buffer/common/sync_token.h"
 #include "gpu/command_buffer/service/client_service_map.h"
 #include "gpu/command_buffer/service/context_group.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
@@ -134,7 +135,7 @@ class GLES2DecoderPassthroughImpl : public GLES2Decoder {
   // returns true if the channel is still scheduled.
   void SetFenceSyncReleaseCallback(
       const FenceSyncReleaseCallback& callback) override;
-  void SetWaitFenceSyncCallback(const WaitFenceSyncCallback& callback) override;
+  void SetWaitSyncTokenCallback(const WaitSyncTokenCallback& callback) override;
   void SetDescheduleUntilFinishedCallback(
       const NoParamCallback& callback) override;
   void SetRescheduleAfterFinishedCallback(
@@ -327,7 +328,7 @@ class GLES2DecoderPassthroughImpl : public GLES2Decoder {
 
   // Callbacks
   FenceSyncReleaseCallback fence_sync_release_callback_;
-  WaitFenceSyncCallback wait_fence_sync_callback_;
+  WaitSyncTokenCallback wait_sync_token_callback_;
 
   // Some objects may generate resources when they are bound even if they were
   // not generated yet: texture, buffer, renderbuffer, framebuffer, transform