gpu: Add flag for enabling asynchronous worker context.

content/browser/gpu/compositor_util.h

Index: content/browser/gpu/compositor_util.h
diff --git a/content/browser/gpu/compositor_util.h b/content/browser/gpu/compositor_util.h
index d66071511a10968f7bcc14869bbdcc9f9ce6c166..5a6cf07c9b74486efd452ff5c208d85f9fd58a84 100644
--- a/content/browser/gpu/compositor_util.h
+++ b/content/browser/gpu/compositor_util.h
@@ -26,6 +26,9 @@ CONTENT_EXPORT bool IsGpuMemoryBufferCompositorResourcesEnabled();
 // Returns true if gpu rasterization is on (via flags) for the renderer.
 CONTENT_EXPORT bool IsGpuRasterizationEnabled();
 
+// returns true if async worker context is on (via flags).
+CONTENT_EXPORT bool IsAsyncWorkerContextEnabled();
+
 // Returns the number of multisample antialiasing samples (via flags) for
 // GPU rasterization.
 CONTENT_EXPORT int GpuRasterizationMSAASampleCount();