Adds support for capturing a sub rect of the compositing surface.

content/public/browser/android/content_view_core.h

Index: content/public/browser/android/content_view_core.h
diff --git a/content/public/browser/android/content_view_core.h b/content/public/browser/android/content_view_core.h
index 0f3503e20d9e89c15d5680154ab07c71fce4827b..ff1db974fc30cf48013396715e95f156fb4a027b 100644
--- a/content/public/browser/android/content_view_core.h
+++ b/content/public/browser/android/content_view_core.h
@@ -11,6 +11,7 @@
 #include "base/callback.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/navigation_controller.h"
+#include "ui/gfx/rect.h"
 
 class SkBitmap;
 
@@ -57,6 +58,7 @@ class CONTENT_EXPORT ContentViewCore {
   virtual void GetScaledContentBitmap(
       float scale,
       jobject bitmap_config,
+      gfx::Rect src_rect,
       const base::Callback<void(bool, const SkBitmap&)>& result_callback) = 0;
   virtual float GetDpiScale() const = 0;
   virtual void PauseVideo() = 0;