Make WebUIImpl a WebContentsObserver to re-use RenderViewCreated()

content/browser/webui/web_ui_impl.h

Index: content/browser/webui/web_ui_impl.h
diff --git a/content/browser/webui/web_ui_impl.h b/content/browser/webui/web_ui_impl.h
index c08db2927f6a33f52350d011adfda47c7f538d4e..21e8a98d18ec962a4a01d0d46c2aa6cdfc1276dd 100644
--- a/content/browser/webui/web_ui_impl.h
+++ b/content/browser/webui/web_ui_impl.h
@@ -11,25 +11,20 @@
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
+#include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_ui.h"
-#include "ipc/ipc_listener.h"
 
 namespace content {
 class RenderFrameHost;
 class RenderViewHost;
 
 class CONTENT_EXPORT WebUIImpl : public WebUI,
-                                 public IPC::Listener,
+                                 public WebContentsObserver,
                                  public base::SupportsWeakPtr<WebUIImpl> {
  public:
   explicit WebUIImpl(WebContents* contents);
   ~WebUIImpl() override;
 
-  // Called by WebContentsImpl when the RenderView is first created. This is
-  // *not* called for every page load because in some cases
-  // RenderFrameHostManager will reuse RenderView instances.
-  void RenderViewCreated(RenderViewHost* render_view_host);
-
   // WebUI implementation:
   WebContents* GetWebContents() const override;
   WebUIController* GetController() const override;
@@ -68,8 +63,9 @@ class CONTENT_EXPORT WebUIImpl : public WebUI,
       const std::string& function_name,
       const std::vector<const base::Value*>& args) override;
 
-  // IPC::Listener implementation:
+  // WebContentsObserver implementation:
   bool OnMessageReceived(const IPC::Message& message) override;
+  void RenderViewCreated(RenderViewHost* render_view_host) override;
 
  private:
   // IPC message handling.