Add GetScrollOffset function to PPB_View

ppapi/cpp/view.h

Index: ppapi/cpp/view.h
diff --git a/ppapi/cpp/view.h b/ppapi/cpp/view.h
index 7ffd1682294412468009cd0d1144dae70df018f7..13c7a81b5871393e06bdcc21e28a31700acb559d 100644
--- a/ppapi/cpp/view.h
+++ b/ppapi/cpp/view.h
@@ -138,6 +138,13 @@ class View : public Resource {
   /// @return A <code>float</code> value representing the number of DIPs per CSS
   /// pixel.
   float GetCSSScale() const;
+
+  /// GetScrollOffset returns the scroll offset of the window containing the
+  /// plugin.
+  ///
+  /// @return A <code>Point</code> which is set to the value of the scroll
+  /// offset in CSS pixels.
+  Point GetScrollOffset() const;
 };
 
 }  // namespace pp