Support frame tree propagation between renderers in the same browsing instance.

content/browser/web_contents/render_view_host_manager.cc

Index: content/browser/web_contents/render_view_host_manager.cc
diff --git a/content/browser/web_contents/render_view_host_manager.cc b/content/browser/web_contents/render_view_host_manager.cc
index 62fec79d74de5e16ec285817f4bc86b6f9eb9689..cbe1d22e24c25073488a3d74e709aadc526db7e0 100644
--- a/content/browser/web_contents/render_view_host_manager.cc
+++ b/content/browser/web_contents/render_view_host_manager.cc
@@ -239,6 +239,23 @@ void RenderViewHostManager::DidNavigateMainFrame(
   }
 }
 
+void RenderViewHostManager::DidUpdateFrameTree(
+    RenderViewHost* render_view_host) {
+  DCHECK(render_view_host == current_host());
+
+  for (RenderViewHostMap::iterator iter = swapped_out_hosts_.begin();
+       iter != swapped_out_hosts_.end();
+       ++iter) {
+    DCHECK(iter->second->GetSiteInstance() !=
+        current_host()->GetSiteInstance());
+
+    iter->second->UpdateFrameTree(
+        render_view_host->GetProcess()->GetID(),
+        render_view_host->GetRoutingID(),
+        render_view_host->GetFrameTree());
+  }
+}
+
 void RenderViewHostManager::SetWebUIPostCommit(WebUIImpl* web_ui) {
   DCHECK(!web_ui_.get());
   web_ui_.reset(web_ui);
@@ -495,6 +512,14 @@ SiteInstance* RenderViewHostManager::GetSiteInstanceForEntry(
     if (entry.IsViewSourceMode())
       return SiteInstance::CreateForURL(browser_context, dest_url);
 
+    // If we are navigating from blank SiteInstance to WebUI, make sure we
+    // create a new one.
+    const WebUIControllerFactory* web_ui_factory =
+        content::GetContentClient()->browser()->GetWebUIControllerFactory();
+    if (web_ui_factory &&
+        web_ui_factory->UseWebUIForURL(browser_context, dest_url))
+        return SiteInstance::CreateForURL(browser_context, dest_url);
+
     // Normally the "site" on the SiteInstance is set lazily when the load
     // actually commits. This is to support better process sharing in case
     // the site redirects to some other site: we want to use the destination
@@ -577,6 +602,17 @@ int RenderViewHostManager::CreateRenderView(
     bool swapped_out) {
   CHECK(instance);
 
+  // If the current host is already in the site instance we are looking for
+  // and we are creating a swapped out renderer, just return the routing id.
+  if (current_host()->GetSiteInstance() == instance) {
+    // TODO(nasko): Convert this if statement to a DCHECK once all causes
+    // of creating a new non-swapped out RVH for the same SiteInstance as the
+    // active one are tracked down and resolved.
+    if (swapped_out) {
+      return current_host()->GetRoutingID();
+    }
+  }
+
   // Check if we've already created an RVH for this SiteInstance.  If so, try
   // to re-use the existing one, which has already been initialized.  We'll
   // remove it from the list of swapped out hosts if it commits.
@@ -607,6 +643,15 @@ int RenderViewHostManager::CreateRenderView(
     if (success) {
       // Don't show the view until we get a DidNavigate from it.
       new_render_view_host->GetView()->Hide();
+
+      // If we are creating a swapped out RVH, send a message to update the
+      // frame tree based on the active RVH for this RenderViewHostManager.
+      if (swapped_out) {
+        new_render_view_host->UpdateFrameTree(
+            current_host()->GetProcess()->GetID(),
+            current_host()->GetRoutingID(),
+            current_host()->GetFrameTree());
+      }
     } else if (!swapped_out) {
       CancelPending();
     }