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 0e48d6863fec65cc668c62f2614dc2e3c8fbb10a..e8798beb7f77b18f8bc9d03c4429653f2a823879 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;
@@ -137,6 +138,8 @@ 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.