gpu: Add sync token dependencies to flush metadata.

gpu/gles2_conform_support/egl/context.cc

Index: gpu/gles2_conform_support/egl/context.cc
diff --git a/gpu/gles2_conform_support/egl/context.cc b/gpu/gles2_conform_support/egl/context.cc
index 6b71251858fbd2b26af45b92122645c38fbb2309..f617144c1aa02977dba2a9b75794b20b35e8368f 100644
--- a/gpu/gles2_conform_support/egl/context.cc
+++ b/gpu/gles2_conform_support/egl/context.cc
@@ -223,7 +223,9 @@ void Context::SignalSyncToken(const gpu::SyncToken& sync_token,
   NOTIMPLEMENTED();
 }
 
-bool Context::CanWaitUnverifiedSyncToken(const gpu::SyncToken* sync_token) {
+void Context::WaitSyncTokenHint(const gpu::SyncToken& sync_token) {}
+
+bool Context::CanWaitUnverifiedSyncToken(const gpu::SyncToken& sync_token) {
   return false;
 }