Create a new RenderFrameHost per child frame when --site-per-process is enabled.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 92112a7ef3239998949b2b27a6b573dc8a7a43af..a528f4327a75192dc645d872832950398d4ac870 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -274,6 +274,13 @@ void NotifyCacheOnIO(
       GetCache()->OnExternalCacheHit(url, http_method);
 }
 
+// Helper function for retrieving all the sites in a frame tree.

[Charlie Reis, 2013/09/24 18:25:58]

Thanks for leaving this part in, but the UMA stats will be broken if we aren't
creating FrameTreeNodes for subframes anymore.  Can we disable the actual UMA
stat collection (maybe in a preliminary CL) so that they're not cluttered with
bad data?  (As things stand, we'll be underestimating the number of processes
since we're ignoring cross-site iframes.)

See site_details.cc from https://chromiumcodereview.appspot.com/16599016, and
feel free to ask me to do it instead.  :)

[awong, 2013/09/26 21:25:24]

Sounds good, but not quite sure how you want me to implement that. Will talk
with you offline.

+bool CollectSites(BrowserContext* context, std::set<GURL>* sites,

[Charlie Reis, 2013/09/24 18:25:58]

Style nit: each parameter should be on its own line if they don't all fit on
one.

[awong, 2013/09/26 21:25:24]

Done.

+                  FrameTreeNode* node) {
+  sites->insert(SiteInstance::GetSiteForURL(context, node->current_url()));
+  return true;
+}
+
 }  // namespace
 
 WebContents* WebContents::Create(const WebContents::CreateParams& params) {
@@ -372,6 +379,10 @@ WebContentsImpl::WebContentsImpl(
       fullscreen_widget_routing_id_(MSG_ROUTING_NONE) {
   for (size_t i = 0; i < g_created_callbacks.Get().size(); i++)
     g_created_callbacks.Get().at(i).Run(this);
+  frame_tree_.SetFrameRemoveListener(
+      base::Bind(&WebContentsImpl::OnFrameRemoved,
+                 base::Unretained(this)));
+
 }
 
 WebContentsImpl::~WebContentsImpl() {
@@ -718,8 +729,6 @@ bool WebContentsImpl::OnMessageReceived(RenderViewHost* render_view_host,
     IPC_MESSAGE_HANDLER(ViewHostMsg_OpenDateTimeDialog,
                         OnOpenDateTimeDialog)
 #endif
-    IPC_MESSAGE_HANDLER(ViewHostMsg_FrameAttached, OnFrameAttached)
-    IPC_MESSAGE_HANDLER(ViewHostMsg_FrameDetached, OnFrameDetached)
     IPC_MESSAGE_HANDLER(ViewHostMsg_MediaNotification, OnMediaNotification)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
@@ -1021,27 +1030,10 @@ uint64 WebContentsImpl::GetUploadPosition() const {
 }
 
 std::set<GURL> WebContentsImpl::GetSitesInTab() const {
-  BrowserContext* browser_context = GetBrowserContext();
   std::set<GURL> sites;
-  if (!frame_tree_root_.get())
-    return sites;
-
-  // Iterates over the FrameTreeNodes to find each unique site URL that is
-  // currently committed.
-  FrameTreeNode* node = NULL;
-  std::queue<FrameTreeNode*> queue;
-  queue.push(frame_tree_root_.get());
-
-  while (!queue.empty()) {
-    node = queue.front();
-    queue.pop();
-    sites.insert(SiteInstance::GetSiteForURL(browser_context,
-                                             node->current_url()));
-
-    for (size_t i = 0; i < node->child_count(); ++i)
-      queue.push(node->child_at(i));
-  }
-
+  frame_tree_.ForEach(Bind(&CollectSites,
+                           base::Unretained(GetBrowserContext()),
+                           base::Unretained(&sites)));
   return sites;
 }
 
@@ -1735,6 +1727,10 @@ SessionStorageNamespace* WebContentsImpl::GetSessionStorageNamespace(
   return controller_.GetSessionStorageNamespace(instance);
 }
 
+FrameTree* WebContentsImpl::GetFrameTree() {
+  return &frame_tree_;
+}
+
 void WebContentsImpl::DidSendScreenRects(RenderWidgetHostImpl* rwh) {
   if (browser_plugin_embedder_)
     browser_plugin_embedder_->DidSendScreenRects();
@@ -2629,52 +2625,6 @@ void WebContentsImpl::OnUpdateFaviconURL(
                     DidUpdateFaviconURL(page_id, candidates));
 }
 
-FrameTreeNode* WebContentsImpl::FindFrameTreeNodeByID(int64 frame_id) {
-  // TODO(nasko): Remove this check once we move to creating the root node
-  // through RenderFrameHost creation.
-  if (!frame_tree_root_.get())
-    return NULL;
-
-  FrameTreeNode* node = NULL;
-  std::queue<FrameTreeNode*> queue;
-  queue.push(frame_tree_root_.get());
-
-  while (!queue.empty()) {
-    node = queue.front();
-    queue.pop();
-    if (node->frame_id() == frame_id)
-      return node;
-
-    for (size_t i = 0; i < node->child_count(); ++i)
-      queue.push(node->child_at(i));
-  }
-
-  return NULL;
-}
-
-void WebContentsImpl::OnFrameAttached(
-    int64 parent_frame_id,
-    int64 frame_id,
-    const std::string& frame_name) {
-  FrameTreeNode* parent = FindFrameTreeNodeByID(parent_frame_id);
-  if (!parent)
-    return;
-
-  FrameTreeNode* node = new FrameTreeNode(frame_id, frame_name);
-  parent->AddChild(node);
-}
-
-void WebContentsImpl::OnFrameDetached(int64 parent_frame_id, int64 frame_id) {
-  FOR_EACH_OBSERVER(WebContentsObserver, observers_,
-                    FrameDetached(message_source_, frame_id));
-
-  FrameTreeNode* parent = FindFrameTreeNodeByID(parent_frame_id);
-  if (!parent)
-    return;
-
-  parent->RemoveChild(frame_id);
-}
-
 void WebContentsImpl::OnMediaNotification(int64 player_cookie,
                                           bool has_video,
                                           bool has_audio,
@@ -3044,12 +2994,10 @@ void WebContentsImpl::DidGetRedirectForResourceRequest(
 void WebContentsImpl::DidNavigate(
     RenderViewHost* rvh,
     const ViewHostMsg_FrameNavigate_Params& params) {
-  // If we don't have a frame tree root yet, this is the first navigation in
-  // using the current RenderViewHost, so we need to create it with the proper
-  // frame id.
-  if (!frame_tree_root_.get()) {
+  if (frame_tree_.IsFirstNavigationAfterSwap()) {
+    // First navigation should be a main frame navigation.
     DCHECK(PageTransitionIsMainFrame(params.transition));
-    frame_tree_root_.reset(new FrameTreeNode(params.frame_id, std::string()));
+    frame_tree_.OnFirstNavigationAfterSwap(params.frame_id);
   }
 
   if (PageTransitionIsMainFrame(params.transition)) {
@@ -3065,10 +3013,6 @@ void WebContentsImpl::DidNavigate(
     render_manager_.DidNavigateMainFrame(rvh);
   }
 
-  // We expect to have a valid frame tree root node at all times when
-  // navigating.
-  DCHECK(frame_tree_root_.get());
-
   // Update the site of the SiteInstance if it doesn't have one yet, unless
   // assigning a site is not necessary for this URL.  In that case, the
   // SiteInstance can still be considered unused until a navigation to a real
@@ -3095,9 +3039,7 @@ void WebContentsImpl::DidNavigate(
   // For now, keep track of each frame's URL in its FrameTreeNode.  This lets
   // us estimate our process count for implementing OOP iframes.
   // TODO(creis): Remove this when we track which pages commit in each frame.
-  FrameTreeNode* node = FindFrameTreeNodeByID(params.frame_id);
-  if (node)
-    node->set_current_url(params.url);
+  frame_tree_.SetFrameUrl(params.frame_id, params.url);
 
   // Send notification about committed provisional loads. This notification is
   // different from the NAV_ENTRY_COMMITTED notification which doesn't include
@@ -3675,24 +3617,6 @@ void WebContentsImpl::NotifySwappedFromRenderManager(RenderViewHost* rvh) {
     view_->SetOverscrollControllerEnabled(delegate_->CanOverscrollContent());
 
   view_->RenderViewSwappedIn(render_manager_.current_host());
-
-  FrameTreeNode* root = NULL;
-  RenderViewHostImpl* new_rvh = static_cast<RenderViewHostImpl*>(
-      render_manager_.current_host());
-
-  // We are doing a cross-site navigation and swapping processes. Since frame
-  // ids are unique to a process, we need to recreate the frame tree with the
-  // proper main frame id.
-  // Note that it is possible for this method to be called before the new RVH
-  // has committed a navigation (if RenderViewHostManager short-circuits the
-  // CommitPending call because the current RVH is dead). In that case, we
-  // haven't heard a valid frame id to use to initialize the root node, so clear
-  // out the root node and the first subsequent navigation message will set it
-  // correctly.
-  if (new_rvh->main_frame_id() != -1)
-    root = new FrameTreeNode(new_rvh->main_frame_id(), std::string());
-
-  frame_tree_root_.reset(root);
 }
 
 int WebContentsImpl::CreateOpenerRenderViewsForRenderManager(
@@ -3866,4 +3790,9 @@ gfx::Size WebContentsImpl::GetSizeForNewRenderView() const {
   return size;
 }
 
+void WebContentsImpl::OnFrameRemoved(int64 frame_id) {
+   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
+                     FrameDetached(message_source_, frame_id));
+}
+
 }  // namespace content