PlzNavigate: Speculatively spawns a renderer process for navigations.

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 7394628bcbf3136c133ebe367c0852818915106c..6d54f6c4476216cf6ef61439d0e2ceb79d0e5951 100644
--- a/content/browser/frame_host/render_frame_host_manager.h
+++ b/content/browser/frame_host/render_frame_host_manager.h
@@ -20,20 +20,20 @@
 #include "content/public/common/referrer.h"
 #include "ui/base/page_transition_types.h"
 
+struct FrameHostMsg_BeginNavigation_Params;

[nasko, 2014/11/10 17:35:31]

Why are these structs outside of the content namespace?

[clamy, 2014/11/12 13:01:13]

They are defined that way in frame_messages.h (and so are resource_messages.h).

[carlosk, 2014/11/13 14:40:26]

Yes, that.

 struct FrameMsg_Navigate_Params;
 
 namespace content {
 class BrowserContext;
 class CrossProcessFrameConnector;
 class CrossSiteTransferringRequest;
-class InterstitialPageImpl;
 class FrameTreeNode;
+class InterstitialPageImpl;
 class NavigationControllerImpl;
 class NavigationEntry;
 class NavigationEntryImpl;
 class RenderFrameHost;
 class RenderFrameHostDelegate;
-class RenderFrameHost;
 class RenderFrameHostImpl;
 class RenderFrameHostManagerTest;
 class RenderFrameProxyHost;
@@ -43,6 +43,7 @@ class RenderWidgetHostDelegate;
 class RenderWidgetHostView;
 class TestWebContents;
 class WebUIImpl;
+struct CommonNavigationParams;
 
 // Manages RenderFrameHosts for a FrameTreeNode. It maintains a
 // current_frame_host() which is the content currently visible to the user. When
@@ -294,6 +295,10 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // Called when a renderer's frame navigates.
   void DidNavigateFrame(RenderFrameHostImpl* render_frame_host);
 
+  // PlzNavigate
+  // Cleans up ongoing navigation data.
+  void CancelNavigation();
+
   // Called when a renderer sets its opener to null.
   void DidDisownOpener(RenderFrameHost* render_frame_host);
 
@@ -362,8 +367,15 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // RenderFrameHostManager. Returns MSG_ROUTING_NONE if none is found.
   int GetRoutingIdForSiteInstance(SiteInstance* site_instance);
 
-  // PlzNavigate: Called when a navigation is ready to commit, to select the
-  // renderer that will commit it.
+  // PlzNavigate
+  // Notifies the RFHM that a navigation is about to begin so that it can
+  // speculatively spawn a new renderer process.

[clamy, 2014/11/12 13:01:13]

nit: add "if needed" at the end of the comment.

[carlosk, 2014/11/13 14:40:26]

Done.

+  void BeginNavigation(const FrameHostMsg_BeginNavigation_Params& params,
+                       const CommonNavigationParams& common_params);
+
+  // PlzNavigate
+  // Called when a navigation is ready to commit, to select the renderer that
+  // will commit it.
   RenderFrameHostImpl* GetFrameHostForNavigation(const GURL& url,
                                                  ui::PageTransition transition);
 
@@ -416,21 +428,32 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
       SiteInstance* dest_instance,
       ui::PageTransition dest_transition,
       bool dest_is_restore,
-      bool dest_is_view_source_mode);
+      bool dest_is_view_source_mode,
+      bool create_unbounded_site_instance);
 
   // Returns an appropriate SiteInstance object for the given |dest_url|,
   // possibly reusing the current SiteInstance.  If --process-per-tab is used,
   // this is only called when ShouldSwapBrowsingInstancesForNavigation returns
   // true. |dest_instance| will be used if it is not null.
   // This is a helper function for GetSiteInstanceForNavigation.
-  SiteInstance* GetSiteInstanceForURL(
-      const GURL& dest_url,
-      SiteInstance* dest_instance,
-      ui::PageTransition dest_transition,
-      bool dest_is_restore,
-      bool dest_is_view_source_mode,
-      SiteInstance* current_instance,
-      bool force_browsing_instance_swap);
+  SiteInstance* GetSiteInstanceForURL(const GURL& dest_url,
+                                      SiteInstance* dest_instance,
+                                      ui::PageTransition dest_transition,
+                                      bool dest_is_restore,
+                                      bool dest_is_view_source_mode,
+                                      SiteInstance* current_instance,
+                                      bool force_browsing_instance_swap,
+                                      bool create_unbounded_site_instance);
+
+  SiteInstance* CreateSiteInstanceForURL(BrowserContext* browser_context,
+                                         const GURL& creation_url,
+                                         bool create_unbounded_site_instance,
+                                         SiteInstanceImpl* current_instance);
+
+  SiteInstance* GetRelatedSiteInstanceForURL(
+      SiteInstanceImpl* current_instance,
+      const GURL& creation_url,
+      bool create_unbounded_site_instance);
 
   // Determines the appropriate url to use as the current url for SiteInstance
   // selection.
@@ -452,6 +475,19 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
                                                         bool swapped_out,
                                                         bool hidden);
 
+  // PlzNavigate
+  // Creates a new RenderFrameHost and does all required supporting work for the
+  // speculative creation of a new renderer for an ongoing navigation request.
+  // This RenderFrameHost might be later destroyed if the final navigation

[nasko, 2014/11/10 17:35:32]

nit: swap the ordering of "later" and "destroyed"

[carlosk, 2014/11/13 14:40:26]

Done.

+  // destination doesn't match the initial one.
+  bool CreateSpeculativeRenderFrameHost(const GURL& url,
+                                        SiteInstance* old_instance,
+                                        SiteInstance* new_instance);
+
+  // PlzNavigate
+  // Cleans up the date related to the speculative RenderFrameHost.
+  void CleanUpSpeculativeRenderFrameHost();
+
   // Sets up the necessary state for a new RenderViewHost with the given opener,
   // if necessary.  It creates a RenderFrameProxy in the target renderer process
   // with the given |proxy_routing_id|, which is used to route IPC messages when
@@ -471,13 +507,21 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // 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.
-  void CommitPending();
+  // With PlzNavigate enabled, |use_speculative_rfh| can be set to true what

[nasko, 2014/11/10 17:35:32]

nit: s/what/which/

[carlosk, 2014/11/13 14:40:26]

Done.

+  // will cause the speculative RenderFrameHost to be the active one.
+  void CommitPending(bool use_speculative_rfh);
 
   // Runs the unload handler in the old RenderFrameHost, after the new
   // RenderFrameHost has committed.  |old_render_frame_host| will either be
   // deleted or put on the pending delete list during this call.
   void SwapOutOldFrame(scoped_ptr<RenderFrameHostImpl> old_render_frame_host);
 
+  // Called to properly discard a created RenderFrameHost that was never made
+  // active (for active ones SwapOutOldFrame is used instead). It can whether be

[nasko, 2014/11/10 17:35:32]

nit: s/whether//

[carlosk, 2014/11/13 14:40:26]

Done.

+  // swapped out or fully destroyed.
+  void RecycleRenderFrameHost(
+      scoped_ptr<RenderFrameHostImpl> render_frame_host);
+
   // Holds |render_frame_host| until it can be deleted when its swap out ACK
   // arrives.
   void MoveToPendingDeleteHosts(
@@ -584,6 +628,16 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
 
   base::WeakPtrFactory<RenderFrameHostManager> weak_factory_;
 
+  // PlzNavigate
+  // Members to store the speculative RFH created upon starting a navigation
+  // allowing the creation of the renderer process as early as possible.
+  // Might be discarded later on if the final URL's SiteInstance doesn't match
+  // what was assumed in the beginning.
+  // Note: speculative RenderFrameHost is only used for PlzNavigate and pending
+  // only for the regular navigation (not yet true, but will be).
+  scoped_ptr<RenderFrameHostImpl> speculative_render_frame_host_;
+  scoped_ptr<WebUIImpl> speculative_web_ui_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderFrameHostManager);
 };