PlzNavigate: implement RequestNavigation in the no live renderer case

content/browser/frame_host/render_frame_host_manager.h

Index: content/browser/frame_host/render_frame_host_manager.h
diff --git a/content/browser/frame_host/render_frame_host_manager.h b/content/browser/frame_host/render_frame_host_manager.h
index 38914e86aaad9949af682704b480d394959bfbd9..ce032140ad6c3498f499e1e2e88ac563cfc9107c 100644
--- a/content/browser/frame_host/render_frame_host_manager.h
+++ b/content/browser/frame_host/render_frame_host_manager.h
@@ -18,6 +18,7 @@
 #include "content/public/common/referrer.h"
 
 struct FrameHostMsg_BeginNavigation_Params;
+struct FrameMsg_Navigate_Params;
 
 namespace content {
 class BrowserContext;
@@ -41,6 +42,7 @@ class RenderWidgetHostDelegate;
 class RenderWidgetHostView;
 class TestWebContents;
 class WebUIImpl;
+struct NavigationBeforeCommitInfo;
 
 // Manages RenderFrameHosts for a FrameTreeNode.  This class acts as a state
 // machine to make cross-process navigations in a frame possible.
@@ -55,6 +57,11 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // There is additional complexity that some of the functions we need in
   // WebContentsImpl are inherited and non-virtual. These are named with
   // "RenderManager" so that the duplicate implementation of them will be clear.
+  //
+  // Functions and parameters whose description are prefixed by PlzNavigate are
+  // part of a navigation refactoring project, currently behind the
+  // enable-browser-side-navigation flag. The idea is to move the logic behind
+  // driving navigations from the renderer to the browser.
   class CONTENT_EXPORT Delegate {
    public:
     // Initializes the given renderer if necessary and creates the view ID
@@ -191,6 +198,12 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // could not be created.
   RenderFrameHostImpl* Navigate(const NavigationEntryImpl& entry);
 
+  // PlzNavigate: sends a RequestNavigation IPC to the renderer to ask it to
+  // navigate. If no live renderer is present, then the navigation request will
+  // be sent directly to the ResourceDispatcherHost.
+  bool RequestNavigation(const NavigationEntryImpl& entry,
+                         const FrameMsg_Navigate_Params& navigate_params);
+
   // Instructs the various live views to stop. Called when the user directed the
   // page to stop loading.
   void Stop();
@@ -250,7 +263,6 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
 
   // Helper method to create and initialize a RenderFrameHost.  If |swapped_out|
   // is true, it will be initially placed on the swapped out hosts list.
-  // Otherwise, it will be used for a pending cross-site navigation.
   // Returns the routing id of the *view* associated with the frame.
   int CreateRenderFrame(SiteInstance* instance,
                         int opener_route_id,
@@ -311,14 +323,18 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // of WebContentsImpl.
   void ResetProxyHosts();
 
-  // Used to start a navigation, part of browser-side navigation project.
-  void OnBeginNavigation(const FrameHostMsg_BeginNavigation_Params& params);
+  // PlzNavigate: Used to start a navigation.

[Charlie Reis, 2014/08/08 20:25:29]

Let's explain whether this happens before or after RequestNavigation.

[clamy, 2014/08/12 12:13:16]

Done.

+  void OnBeginNavigation(const FrameHostMsg_BeginNavigation_Params& params,
+                         const NavigationEntryImpl& entry);
 
   // Returns the routing id for a RenderFrameHost or RenderFrameHostProxy
   // that has the given SiteInstance and is associated with this
   // RenderFrameHostManager. Returns MSG_ROUTING_NONE if none is found.
   int GetRoutingIdForSiteInstance(SiteInstance* site_instance);
 
+  // PlzNavigate: Used to signal the commit of a navigation request.

[Charlie Reis, 2014/08/08 20:25:29]

In retrospect, this comment isn't very clear, partly because of how the code
used to work.  The name sounds like CommitPending, which occurs *after* the
navigation has committed in the renderer.  In contrast, this function is closer
to the current OnCrossSiteResponse, which means the network response is ready to
commit but hasn't yet.

I'm not sure I have a better suggestion for the name (CommitNavigation and
DidCommitNavigation might end up as a reasonable pair of functions), but we
should at least be very explicit about which point of the timeline this
represents in the comment.

(This also applies in navigator.h.)

[clamy, 2014/08/12 12:13:16]

Is the comment now clearer?

+  void CommitNavigation(const NavigationBeforeCommitInfo& info);
+
  private:
   friend class RenderFrameHostManagerTest;
   friend class TestWebContents;
@@ -402,15 +418,27 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
       const NavigationEntry* current_entry,
       const NavigationEntryImpl* new_entry) const;
 
-  // Returns an appropriate SiteInstance object for the given NavigationEntry,
-  // possibly reusing the current SiteInstance.  If --process-per-tab is used,
-  // this is only called when ShouldSwapBrowsingInstancesForNavigation returns
-  // true.
+  // Returns the SiteInstance to use for the navigation.
+  SiteInstance* GetSiteInstanceForNavigation(const NavigationEntryImpl& entry);
+
+  // Helper function that returns an appropriate SiteInstance object for the
+  // given NavigationEntry, possibly reusing the current SiteInstance.  If
+  // --process-per-tab is used, this is only called when
+  // ShouldSwapBrowsingInstancesForNavigation returns true. Caller should use
+  // GetSiteInstanceForNavigation.
   SiteInstance* GetSiteInstanceForEntry(
       const NavigationEntryImpl& entry,
       SiteInstance* current_instance,
       bool force_browsing_instance_swap);
 
+  // Creates a new RenderFrameHostImpl for the |new_instance| while respecting
+  // the opener route if needed and stores it in pending_render_frame_host_.
+  // Also returns a pointer to the newly created RFH.
+  RenderFrameHostImpl* CreateRenderFrameHostForNewSiteInstance(
+      SiteInstance* old_instance,
+      SiteInstance* new_instance,
+      bool is_main_frame);
+
   // Creates a RenderFrameHost and corresponding RenderViewHost if necessary.
   scoped_ptr<RenderFrameHostImpl> CreateRenderFrameHost(SiteInstance* instance,
                                                         int view_routing_id,
@@ -434,6 +462,11 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // above.
   bool InitRenderFrame(RenderFrameHost* render_frame_host);
 
+  // Initializes |dest_render_frame_host| and |render_frame_host_| if necessary
+  // before navigating.
+  bool InitRenderFrameHostsBeforeNavigation(
+      RenderFrameHostImpl* dest_render_frame_host);
+
   // Sets the pending RenderFrameHost/WebUI to be the active one. Note that this
   // doesn't require the pending render_frame_host_ pointer to be non-NULL,
   // since there could be Web UI switching as well. Call this for every commit.
@@ -525,7 +558,8 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
 
   NotificationRegistrar registrar_;
 
-  // Owns a navigation request that originated in that frame until it commits.
+  // PlzNavigate: Owns a navigation request that originated in that frame until
+  // it commits.
   scoped_ptr<NavigationRequest> navigation_request_;
 
   base::WeakPtrFactory<RenderFrameHostManager> weak_factory_;