PlzNavigate: Speculatively spawns a renderer process for navigations.

content/test/test_web_contents.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/test/test_web_contents.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "content/browser/browser_url_handler_impl.h"
@@ skipping 44 matching lines @@
 TestRenderViewHost* TestWebContents::GetRenderViewHost() const {
     return static_cast<TestRenderViewHost*>(
         WebContentsImpl::GetRenderViewHost());
 }
 
 TestRenderFrameHost* TestWebContents::GetPendingMainFrame() const {
   return static_cast<TestRenderFrameHost*>(
       GetRenderManager()->pending_frame_host());
 }
 
+TestRenderFrameHost* TestWebContents::GetSpeculativeMainFrame() const {
+  return static_cast<TestRenderFrameHost*>(
+      GetRenderManager()->speculative_render_frame_host_.get());
+}
+
 void TestWebContents::TestDidNavigate(RenderFrameHost* render_frame_host,
                                       int page_id,
                                       const GURL& url,
                                       ui::PageTransition transition) {
   TestDidNavigateWithReferrer(render_frame_host,
                               page_id,
                               url,
                               Referrer(),
                               transition);
 }
@@ skipping 89 matching lines @@
 void TestWebContents::TestSetIsLoading(bool value) {
   SetIsLoading(GetRenderViewHost(), value, true, NULL);
 }
 
 void TestWebContents::CommitPendingNavigation() {
   // If we are doing a cross-site navigation, this simulates the current RVH
   // notifying that it has unloaded so the pending RVH is resumed and can
   // navigate.
   ProceedWithCrossSiteNavigation();
   TestRenderFrameHost* old_rfh = GetMainFrame();
-  TestRenderFrameHost* rfh = GetPendingMainFrame();
+  TestRenderFrameHost* rfh;
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableBrowserSideNavigation)) {
+    rfh = GetSpeculativeMainFrame();

[clamy, 2014/12/19 13:35:57]

This is one of the cases where having a method that returns either the pending
or the speculative RFH would come in handy.

[carlosk, 2014/12/29 16:40:16]

Done.

+  } else {
+    rfh = GetPendingMainFrame();
+  }
+
   if (!rfh)
     rfh = old_rfh;
 
   const NavigationEntry* entry = GetController().GetPendingEntry();
   DCHECK(entry);
   int page_id = entry->GetPageID();
   if (page_id == -1) {
     // It's a new navigation, assign a never-seen page id to it.
     page_id = GetMaxPageIDForSiteInstance(rfh->GetSiteInstance()) + 1;
   }
 
   rfh->SendNavigate(page_id, entry->GetURL());
   // Simulate the SwapOut_ACK. This is needed when cross-site navigation happens
   // (old_rfh != rfh).
   if (old_rfh != rfh)
     old_rfh->OnSwappedOut();
 }
 
 void TestWebContents::ProceedWithCrossSiteNavigation() {
-  if (!GetPendingMainFrame())
+  // Note: At the moment in the navigation process when this method is called

[nasko, 2014/12/20 00:09:09]

nit: s/process/progress/

[carlosk, 2014/12/29 16:40:17]

(comment was removed)

+  // (after the RenderFrameHost committed), the speculative RenderFrameHost, if

[nasko, 2014/12/20 00:09:09]

"(after the RenderFrameHost committed)" Is this actually true? The fact that the
code later sends the BeforeUnloadACK it means that the navigation hasn't
committed, though it has started.

[carlosk, 2014/12/29 16:40:17]

What I meant was that the call to RFH::CommitNavigation aldready happened (it
happens when we call CallOnResponseStarted on the loader). Is that not what we
mean by the RFH having committed? 

But this comment was removed anyway.

[clamy, 2014/12/29 17:36:21]

In the current code path this function is called before the navigation has even
started. The navigation can only start when the BeforeUnload ack has been
received, which is what the function simulates.

[carlosk, 2014/12/30 15:54:50]

Acknowledged. What I said before was wrong...

+  // any, is already guaranteed to be the one that will be made active. That's
+  // why this works.
+  if (!GetPendingMainFrame() && !GetSpeculativeMainFrame())

[clamy, 2014/12/19 13:35:57]

This function should only be called at the beginning of a cross-site navigation
in the current codepath. In PlzNavigate, the execution of the BeforeUnload
handler is to be done through the RequestNavigation/BeginNavigation pair.

Therefore, what you should do here is return immediately when PlzNavigate is
enabled, or have a DCHECK PlzNavigate is not enabled, and make sure we don't
call it when it is.

[carlosk, 2014/12/29 16:40:17]

Done the 1st option as it eases things.

     return;
   GetMainFrame()->SendBeforeUnloadACK(true);
 }
 
 RenderViewHostDelegateView* TestWebContents::GetDelegateView() {
   if (delegate_view_override_)
     return delegate_view_override_;
   return WebContentsImpl::GetDelegateView();
 }
 
@@ skipping 65 matching lines @@
 }
 
 void TestWebContents::ShowCreatedWidget(int route_id,
                                         const gfx::Rect& initial_pos) {
 }
 
 void TestWebContents::ShowCreatedFullscreenWidget(int route_id) {
 }
 
 }  // namespace content