[DevTools] Do not sniff FrameMsg_Navigate in DevToolsAgent

This will be impossible when switching to Mojo. Using a direct
call instead.

Bug: 776009
Change-Id: I766e9d711cd1ac9f6aa7c0c08622930a493d5041
Reviewed-on: https://chromium-review.googlesource.com/772838
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516972}

content/renderer/devtools/devtools_agent.cc

@@ -109,10 +109,6 @@ bool DevToolsAgent::OnMessageReceived(const IPC::Message& message) {
                         OnRequestNewWindowACK)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
-
-  if (message.type() == FrameMsg_Navigate::ID)
-    ContinueProgram();  // Don't want to swallow the message.
-
   return handled;
 }
 

content/renderer/devtools/devtools_agent.h

@@ -47,6 +47,7 @@ class CONTENT_EXPORT DevToolsAgent : public RenderFrameObserver,
 
   bool IsAttached();
   void DetachAllSessions();
+  void ContinueProgram();
 
  private:
   friend class DevToolsAgentTest;
@@ -83,7 +84,6 @@ class CONTENT_EXPORT DevToolsAgent : public RenderFrameObserver,
                                     const std::string& message);
   void OnInspectElement(int session_id, int x, int y);
   void OnRequestNewWindowACK(int session_id, bool success);
-  void ContinueProgram();
 
   void GotManifest(int session_id,
                    int command_id,

content/renderer/render_frame_impl.cc

@@ -1864,6 +1864,8 @@ void RenderFrameImpl::OnNavigate(
   DCHECK(!IsBrowserSideNavigationEnabled());
   TRACE_EVENT2("navigation,rail", "RenderFrameImpl::OnNavigate", "id",
                routing_id_, "url", common_params.url.possibly_invalid_spec());
+  if (devtools_agent_)
+    devtools_agent_->ContinueProgram();
   NavigateInternal(common_params, start_params, request_params,
                    std::unique_ptr<StreamOverrideParameters>(),
                    /*subresource_loader_factories=*/base::nullopt);