API tweaks to PixelCopy and make it public

Bug: 27708453
Change-Id: I81667ce42f9ca1c1a13e1e61299927900845fc84
diff --git a/libs/hwui/renderthread/RenderProxy.h b/libs/hwui/renderthread/RenderProxy.h
index c39319d..898b314 100644
--- a/libs/hwui/renderthread/RenderProxy.h
+++ b/libs/hwui/renderthread/RenderProxy.h
@@ -127,7 +127,7 @@
     ANDROID_API void removeFrameMetricsObserver(FrameMetricsObserver* observer);
     ANDROID_API long getDroppedFrameReportCount();
 
-    ANDROID_API static bool copySurfaceInto(sp<Surface>& surface, SkBitmap* bitmap);
+    ANDROID_API static int copySurfaceInto(sp<Surface>& surface, SkBitmap* bitmap);
 
 private:
     RenderThread& mRenderThread;