PlzNavigate: add support in several navigation controller unit tests

content/browser/frame_host/navigation_request.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_NAVIGATION_REQUEST_H_
 #define CONTENT_BROWSER_FRAME_HOST_NAVIGATION_REQUEST_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/browser/loader/navigation_url_loader_delegate.h"
 #include "content/common/content_export.h"
 #include "content/common/navigation_params.h"
 
 namespace content {
 
 class FrameTreeNode;
 class NavigationURLLoader;
 class ResourceRequestBody;
 struct NavigationRequestInfo;
 
 // PlzNavigate
 // A UI thread object that owns a navigation request until it commits. It
 // ensures the UI thread can start a navigation request in the
 // ResourceDispatcherHost (that lives on the IO thread).
 // TODO(clamy): Describe the interactions between the UI and IO thread during
 // the navigation following its refactoring.
 class CONTENT_EXPORT NavigationRequest : public NavigationURLLoaderDelegate {
  public:
+  // Keeps track of the various stages of a NavigationRequest.
+  enum NavigationState {
+    // Initial state.
+    NOT_STARTED = 0,
+
+    // Waiting for a BeginNavigation IPC from the renderer. If there is no live
+    // renderer when the request is created, this stage is skipped.

[nasko, 2014/12/17 19:55:38]

The no live renderer is only for browser-initiated navigations, right? Also,
when we optimize out roundtrip because no beforeunload handlers are registered,
we will skip it too, right?
Just want to make sure I understand it correctly.

[clamy, 2014/12/18 13:54:42]

This stage only happens in browser initiated navigations. Yes I think we will be
able to optimize this step out for cross-site navigations where the old page has
no BeforeUnload handler registered.

+    WAITING_FOR_RENDERER_RESPONSE,
+
+    // The request was sent to the IO thread.
+    STARTED,
+
+    // The response started on the IO thread and is ready to be committed. This
+    // is one of the two final states for the request.
+    RESPONSE_STARTED,
+
+    // The request failed on the IO thread and an error page should be
+    // displayed. This is one of the two final states for the request.
+    FAILED,
+  };
+
   NavigationRequest(FrameTreeNode* frame_tree_node,
                     const CommonNavigationParams& common_params,
                     const CommitNavigationParams& commit_params);
 
   ~NavigationRequest() override;
 
   // Called on the UI thread by the RenderFrameHostManager which owns the
   // NavigationRequest. Takes ownership of |info|. After calling this function,
   // |body| can no longer be manipulated on the UI thread.
   void BeginNavigation(scoped_ptr<NavigationRequestInfo> info,
                        scoped_refptr<ResourceRequestBody> body);
 
   CommonNavigationParams& common_params() { return common_params_; }
 
   const CommitNavigationParams& commit_params() const { return commit_params_; }
 
   NavigationURLLoader* loader_for_testing() const { return loader_.get(); }
 
+  NavigationState state() const { return state_; }
+
+  void SetWaitingForRendererResponse() {
+    state_ = WAITING_FOR_RENDERER_RESPONSE;

[nasko, 2014/12/17 19:55:38]

nit: DCHECK we aren't already in this state?

[clamy, 2014/12/18 13:54:42]

In fact it is even DCHECK that the state is NOT_STARTED.

+  }
+
  private:
   // NavigationURLLoaderDelegate implementation.
   void OnRequestRedirected(
       const net::RedirectInfo& redirect_info,
       const scoped_refptr<ResourceResponse>& response) override;
   void OnResponseStarted(const scoped_refptr<ResourceResponse>& response,
                          scoped_ptr<StreamHandle> body) override;
   void OnRequestFailed(int net_error) override;
 
   FrameTreeNode* frame_tree_node_;
 
   // Initialized on creation of the NavigationRequest. Sent to the renderer when
   // the navigation is ready to commit.
   // Note: When the navigation is ready to commit, the url in |common_params|
   // will be set to the final navigation url, obtained after following all
   // redirects.
   CommonNavigationParams common_params_;
   const CommitNavigationParams commit_params_;
 
+  NavigationState state_;
+
   scoped_ptr<NavigationURLLoader> loader_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationRequest);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATION_REQUEST_H_