Make WebUIImpl a WebContentsObserver to re-use RenderViewCreated()

content/browser/webui/web_ui_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/webui/web_ui_impl.h"
 
 #include "base/json/json_writer.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "content/browser/child_process_security_policy_impl.h"
@@ skipping 26 matching lines @@
       parameters += base::char16(',');
 
     base::JSONWriter::Write(*arg_list[i], &json);
     parameters += base::UTF8ToUTF16(json);
   }
   return base::ASCIIToUTF16(function_name) +
       base::char16('(') + parameters + base::char16(')') + base::char16(';');
 }
 
 WebUIImpl::WebUIImpl(WebContents* contents)
-    : link_transition_type_(ui::PAGE_TRANSITION_LINK),
+    : WebContentsObserver(contents),
+      link_transition_type_(ui::PAGE_TRANSITION_LINK),
       bindings_(BINDINGS_POLICY_WEB_UI),
       web_contents_(contents) {
   DCHECK(contents);
 }
 
 WebUIImpl::~WebUIImpl() {
   // Delete the controller first, since it may also be keeping a pointer to some
   // of the handlers and can call them at destruction.
   controller_.reset();
 }
@@ skipping 17 matching lines @@
       !WebUIControllerFactoryRegistry::GetInstance()->IsURLAcceptableForWebUI(
           web_contents_->GetBrowserContext(), source_url)) {
     NOTREACHED() << "Blocked unauthorized use of WebUIBindings.";
     return;
   }
 
   ProcessWebUIMessage(source_url, message, args);
 }
 
 void WebUIImpl::RenderViewCreated(RenderViewHost* render_view_host) {
   controller_->RenderViewCreated(render_view_host);

[Charlie Reis, 2015/08/28 17:05:56]

Do we need to check whether this is our RVH before acting on it?

For example, suppose we're on chrome://version and then navigate to
chromium.org.  WebContentsObserver::RenderViewCreated will get called for the
pending, non-WebUI RVH, and the chrome://version WebUIImpl object will hear
about it.

Would checking whether the RVH's SiteInstance matches the target frame's
SiteInstance might work?

 }
 
 WebContents* WebUIImpl::GetWebContents() const {
   return web_contents_;
 }
 
 float WebUIImpl::GetDeviceScaleFactor() const {
   return GetScaleFactorForView(web_contents_->GetRenderWidgetHostView());
 }
 
@@ skipping 145 matching lines @@
 }
 
 void WebUIImpl::AddToSetIfFrameNameMatches(
     std::set<RenderFrameHost*>* frame_set,
     RenderFrameHost* host) {
   if (host->GetFrameName() == frame_name_)
     frame_set->insert(host);
 }
 
 }  // namespace content