FrameTree::Find only searches relative to local frames.

third_party/WebKit/Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 2615 matching lines @@
   if (!page_->DeprecatedLocalMainFrame()->GetDocument()->Loader())
     return WebString();
 
   return page_->DeprecatedLocalMainFrame()->GetDocument()->EncodingName();
 }
 
 WebFrame* WebViewImpl::MainFrame() {
   return WebFrame::FromFrame(page_ ? page_->MainFrame() : nullptr);
 }
 
-WebFrame* WebViewImpl::FindFrameByName(const WebString& name,
-                                       WebFrame* relative_to_frame) {
-  // FIXME: Either this should only deal with WebLocalFrames or it should move
-  // to WebFrame.
-  if (!relative_to_frame)
-    relative_to_frame = MainFrame();
-  Frame* frame = ToWebLocalFrameBase(relative_to_frame)->GetFrame();
-  frame = frame->Tree().Find(name);
-  if (!frame || !frame->IsLocalFrame())
-    return nullptr;
-  return WebLocalFrameBase::FromFrame(ToLocalFrame(frame));
-}
-
 WebLocalFrame* WebViewImpl::FocusedFrame() {
   Frame* frame = FocusedCoreFrame();
   // TODO(yabinh): focusedCoreFrame() should always return a local frame, and
   // the following check should be unnecessary.
   // See crbug.com/625068
   if (!frame || !frame->IsLocalFrame())
     return nullptr;
   return WebLocalFrameBase::FromFrame(ToLocalFrame(frame));
 }
 
@@ skipping 1492 matching lines @@
   if (focused_frame->LocalFrameRoot() != MainFrameImpl()->GetFrame())
     return nullptr;
   return focused_frame;
 }
 
 LocalFrame* WebViewImpl::FocusedLocalFrameAvailableForIme() const {
   return ime_accept_events_ ? FocusedLocalFrameInWidget() : nullptr;
 }
 
 }  // namespace blink