Make the number of raster threads appear in chrome://gpu.

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 3ce396e384b14bd115d2eedc22c95afe990147b5..149863c211426addc32877016b750e266f7a75a8 100644
--- a/content/browser/gpu/compositor_util.h
+++ b/content/browser/gpu/compositor_util.h
@@ -30,6 +30,13 @@ CONTENT_EXPORT bool IsGpuRasterizationEnabled();
 // Returns true if force-gpu-rasterization is on (via flags) for the renderer.
 CONTENT_EXPORT bool IsForceGpuRasterizationEnabled();
 
+// Returns the number of raster threads to use for compositing.
+CONTENT_EXPORT int NumberOfRendererRasterThreads();
+
+// Returns the number of raster threads to use for compositing that are forced
+// by the command line.
+CONTENT_EXPORT int ForceNumberOfRendererRasterThreads();
+
 CONTENT_EXPORT base::Value* GetFeatureStatus();
 CONTENT_EXPORT base::Value* GetProblems();
 CONTENT_EXPORT base::Value* GetDriverBugWorkarounds();