PlzNavigate: identify same-page browser-initiated navigation.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index c42b652ded6a67958017054adbe9120a359087a5..8c48498c38ba8765b12c868f056a220932cae98a 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -2618,6 +2618,8 @@ void RenderFrameHostImpl::CommitNavigation(
   DCHECK((response && body.get()) ||
          common_params.url.SchemeIs(url::kDataScheme) ||
          !ShouldMakeNetworkRequestForURL(common_params.url) ||
+         request_params.is_same_document_fragment_change ||
+         request_params.is_same_document_history_load ||
          IsRendererDebugURL(common_params.url));
   UpdatePermissionsForNavigation(common_params, request_params);
 
@@ -2640,8 +2642,11 @@ void RenderFrameHostImpl::CommitNavigation(
                                      request_params));
 
   // If a network request was made, update the LoFi state.
-  if (ShouldMakeNetworkRequestForURL(common_params.url))
+  if (ShouldMakeNetworkRequestForURL(common_params.url) &&
+      !request_params.is_same_document_fragment_change &&
+      !request_params.is_same_document_history_load) {
     last_navigation_lofi_state_ = common_params.lofi_state;
+  }
 
   // TODO(clamy): Release the stream handle once the renderer has finished
   // reading it.
@@ -3316,14 +3321,25 @@ void RenderFrameHostImpl::OnMediaInterfaceFactoryConnectionError() {
 std::unique_ptr<NavigationHandleImpl>
 RenderFrameHostImpl::TakeNavigationHandleForCommit(
     const FrameHostMsg_DidCommitProvisionalLoad_Params& params) {
+  bool is_browser_initiated = (params.nav_entry_id != 0);
+
   // If this is a same-page navigation, there isn't an existing NavigationHandle
   // to use for the navigation. Create one, but don't reset any NavigationHandle
   // tracking an ongoing navigation, since this may lead to the cancellation of
   // the navigation.
+  // PlzNavigate: This doesn't apply for browser-initiated same-page navigation,
+  // because a NavigationHandle is created.
   if (params.was_within_same_page) {
+    if (IsBrowserSideNavigationEnabled() && is_browser_initiated &&
+        navigation_handle_ && navigation_handle_->IsSamePage() &&
+        navigation_handle_->GetURL() == params.url) {

[nasko, 2017/01/10 00:19:00]

Why is the URL check needed here? Also, if it is a fragment change, wouldn't
that still be a same-page navigation, but fail the strict URL match here?

[clamy, 2017/01/10 10:52:54]

This is checking whether we are comitting a navigation that matches the handle
we created in the first place. If the navigation is the one that created the
handle, the strict url check should match.

[arthursonzogni, 2017/01/12 17:32:30]

Yes, we have to check that the current navigation_handle is the one that
initiated the navigation.

Sometimes, it's not the case, for instance:
The browser initiate a same-page navigation. The renderer commit it, but before
that the confirmation is sent back to the browser, the browser initiate another
navigation and replace the current navigation_handle by the new one.
In that case, the new navigation_handle is not reused but a new one is created.

I preserve the old behavior by creating a new navigation_handle if the current
one is not available. Is there anything that could goes wrong with this?

+      return std::move(navigation_handle_);
+    }
+
     // We don't ever expect navigation_handle_ to match, because handles are not
     // created for same-page navigations.
-    DCHECK(!navigation_handle_ || !navigation_handle_->IsSamePage());
+    DCHECK(IsBrowserSideNavigationEnabled() || !navigation_handle_ ||
+           !navigation_handle_->IsSamePage());
 
     // First, determine if the navigation corresponds to the pending navigation
     // entry. This is the case for a browser-initiated same-page navigation,