Check BrowsingInstance before swapping prerenders.

content/browser/frame_host/render_frame_host_manager_unittest.cc

Index: content/browser/frame_host/render_frame_host_manager_unittest.cc
diff --git a/content/browser/frame_host/render_frame_host_manager_unittest.cc b/content/browser/frame_host/render_frame_host_manager_unittest.cc
index c0afa6718885eef93b86cdd0888ecee92c5869bc..8e44208c5d5f841e91a5c585e5f55e166ba27f5a 100644
--- a/content/browser/frame_host/render_frame_host_manager_unittest.cc
+++ b/content/browser/frame_host/render_frame_host_manager_unittest.cc
@@ -1049,6 +1049,14 @@ TEST_F(RenderFrameHostManagerTest, WebUI) {
                             false /* is_renderer_init */);
   RenderFrameHostImpl* host = manager->Navigate(entry);
 
+  // This test creates a second FrameTree for the WebContents which throws off
+  // some of the accounting. This inverts what was done in
+  // WebContentsImpl::NotifySwapped.
+  static_cast<SiteInstanceImpl*>(instance)->
+      IncrementRelatedActiveContentsCount();
+  static_cast<SiteInstanceImpl*>(host->GetSiteInstance())->
+      DecrementRelatedActiveContentsCount();

[davidben, 2014/04/28 18:34:39]

Not super-thrilled about this bit. Another possibility is some kind of
WebContentsImpl::SetUsingExternalFrameTreeForTesting(). Another possibility is
to move the accounting into top-level RFHMs.

[Charlie Reis, 2014/04/29 22:13:51]

I'm not entirely sure why we need a separate FrameTree in this test in the first
place.  Looks like it was a legacy thing of creating a fresh RVHM for the test
using the existing WebContents as a mostly-unused delegate, but I don't see a
reason why we can't just use the RFHM of the WebContents itself.  See:
https://codereview.chromium.org/117693002/diff/20001/content/browser/frame_ho...

The test seems to pass if we replace tree, manager, and the Init call with:
RenderFrameHostManager* manager = web_contents->GetRenderManagerForTesting();

Same below.

[davidben, 2014/04/29 23:02:25]

Oh. Well then. Handy. I've gone and fixed those.

+
   // We commit the pending RenderFrameHost immediately because the previous
   // RenderFrameHost was not live.  We test a case where it is live in
   // WebUIInNewTab.
@@ -1115,6 +1123,14 @@ TEST_F(RenderFrameHostManagerTest, WebUIInNewTab) {
   EXPECT_TRUE(
       host1->render_view_host()->GetEnabledBindings() & BINDINGS_POLICY_WEB_UI);
 
+  // This test creates a second FrameTree for the WebContents which throws off
+  // some of the accounting. This inverts what was done in
+  // WebContentsImpl::NotifySwapped.
+  static_cast<SiteInstanceImpl*>(blank_instance)->
+      IncrementRelatedActiveContentsCount();
+  static_cast<SiteInstanceImpl*>(host1->GetSiteInstance())->
+      DecrementRelatedActiveContentsCount();
+

[davidben, 2014/04/28 18:34:39]

Ditto.

   // Now simulate clicking a link that opens in a new tab.
   scoped_ptr<TestWebContents> web_contents2(
       TestWebContents::Create(browser_context(), webui_instance));