Preparation steps for adding speculative renderer creation.

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 c40cac4db9e694ea8fe43b6cb7bbe78ca7336497..57905a05cbb94d464a069fde594580f685df27a4 100644
--- a/content/browser/frame_host/render_frame_host_manager.h
+++ b/content/browser/frame_host/render_frame_host_manager.h
@@ -26,14 +26,13 @@ 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;
@@ -231,10 +230,6 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
                                    pending_and_current_web_ui_.get();
   }
 
-  // Sets the pending Web UI for the pending navigation, ensuring that the
-  // bindings are appropriate compared to |bindings|.
-  void SetPendingWebUI(const GURL& url, int bindings);
-
   // Called when we want to instruct the renderer to navigate to the given
   // navigation entry. It may create a new RenderFrameHost or re-use an existing
   // one. The RenderFrameHost to navigate will be returned. Returns NULL if one
@@ -297,11 +292,20 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // Called when a renderer sets its opener to null.
   void DidDisownOpener(RenderFrameHost* render_frame_host);
 
-  // Helper method to create and initialize a RenderFrameHost.  If |flags|
-  // has the CREATE_RF_SWAPPED_OUT bit set from the CreateRenderFrameFlags
-  // enum, it will initially be placed on the swapped out hosts list.
-  // Returns the routing id of the *view* associated with the frame.
-  int CreateRenderFrame(SiteInstance* instance, int opener_route_id, int flags);
+  // Sets the pending Web UI for the pending navigation, ensuring that the
+  // bindings are appropriate compared to |bindings|.
+  void SetPendingWebUI(const GURL& url, int bindings);
+
+  // Creates and initializes a RenderFrameHost. If |flags| has the
+  // CREATE_RF_SWAPPED_OUT bit set from the CreateRenderFrameFlags enum, it will
+  // initially be placed on the swapped out hosts list. If |routing_id_ptr| is
+  // not nullptr it will be set to the routing id of the *view* associated with
+  // the frame.
+  scoped_ptr<RenderFrameHostImpl> CreateRenderFrame(SiteInstance* instance,
+                                                    int opener_route_id,
+                                                    int flags,
+                                                    const WebUIImpl* web_ui,

[Charlie Reis, 2014/11/26 00:42:54]

DRAFT: This seems like a strange type.

[Charlie Reis, 2014/11/26 01:06:40]

At the moment, it's hard to tell what this parameter is for.  const& would be
more common than const*, and it's confusing that it's a raw pointer next to an
out parameter (so at first it looked like another out parameter).

I suggest dropping the const and moving it to be the second parameter.  Please
also document it in the comment.

[carlosk, 2014/11/27 11:02:44]

Done.

I agree it was confusing and I was in doubt on how to handle that one. It is an
input parameter but it's an optional one hence it being a const pointer.

+                                                    int* routing_id_ptr);

[Charlie Reis, 2014/11/26 00:42:54]

We should put "view" in the name of this parameter, now that we can.

[carlosk, 2014/11/27 11:02:44]

Done.

 
   // Helper method to create and initialize a RenderFrameProxyHost and return
   // its routing id.
@@ -401,6 +405,10 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
       const GURL& new_effective_url,
       bool new_is_view_source_mode) const;
 
+  // Creates a new Web UI, ensuring that the bindings are appropriate compared
+  // to |bindings|. The caller is responsible for the instance ownership.

[Charlie Reis, 2014/11/26 01:06:40]

Yes, should return a scoped_ptr then.

[carlosk, 2014/11/27 11:02:44]

Done. I also removed that extra comment as the scoped_ptr makes ownership 
explicit.

+  WebUIImpl* CreateWebUI(const GURL& url, int bindings);
+
   // Returns true if it is safe to reuse the current WebUI when navigating from
   // |current_entry| to |new_url|.
   bool ShouldReuseWebUI(
@@ -442,6 +450,13 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
       SiteInstance* new_instance,
       bool is_main_frame);
 
+  // Ensure that we have created RFHs for the new RFH's opener chain if
+  // we are staying in the same BrowsingInstance. This allows the new RFH
+  // to send cross-process script calls to its opener(s). Returns the opener
+  // route ID to be used for the new RenderView to be created.
+  int CreateOpenerRenderViewsIfNeeded(SiteInstance* old_instance,
+                                      SiteInstance* new_instance);
+
   // Creates a RenderFrameHost and corresponding RenderViewHost if necessary.
   scoped_ptr<RenderFrameHostImpl> CreateRenderFrameHost(SiteInstance* instance,
                                                         int view_routing_id,
@@ -474,6 +489,11 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // deleted or put on the pending delete list during this call.
   void SwapOutOldFrame(scoped_ptr<RenderFrameHostImpl> old_render_frame_host);
 
+  // Discards a RenderFrameHost that was never made active (for active ones
+  // SwapOutOldFrame is used instead).
+  void DiscardRenderFrameHost(

[Charlie Reis, 2014/11/26 00:42:54]

DiscardUnusedRenderFrameHost (or DiscardUnusedFrame) would be clearer (vs
SwapOutOldFrame).

[carlosk, 2014/11/27 11:02:44]

Done.

+      scoped_ptr<RenderFrameHostImpl> render_frame_host);
+
   // Holds |render_frame_host| until it can be deleted when its swap out ACK
   // arrives.
   void MoveToPendingDeleteHosts(