Move GetDocument method from WebFrame to WebLocalFrame.

third_party/WebKit/public/web/WebLocalFrame.h

Index: third_party/WebKit/public/web/WebLocalFrame.h
diff --git a/third_party/WebKit/public/web/WebLocalFrame.h b/third_party/WebKit/public/web/WebLocalFrame.h
index 0f9bdc606655aec9d9e645e4ce0103d71ade73c2..5e49f008712a4e11ff5e49deb478a27d84f24fc5 100644
--- a/third_party/WebKit/public/web/WebLocalFrame.h
+++ b/third_party/WebKit/public/web/WebLocalFrame.h
@@ -32,6 +32,7 @@ class WebData;
 class WebDataSource;
 class WebDevToolsAgent;
 class WebDevToolsAgentClient;
+class WebDocument;
 class WebDoubleSize;
 class WebDOMEvent;
 class WebFrameClient;
@@ -138,6 +139,8 @@ class WebLocalFrame : public WebFrame {
   // URLs
   virtual WebVector<WebIconURL> IconURLs(int icon_types_mask) const = 0;
 
+  virtual WebDocument GetDocument() const = 0;
+
   // Hierarchy ----------------------------------------------------------
 
   // Get the highest-level LocalFrame in this frame's in-process subtree.