PlzNavigate: identify same-page browser-initiated navigation.

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 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/browser/frame_host/render_frame_host_impl.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 2600 matching lines @@
 // PlzNavigate
 void RenderFrameHostImpl::CommitNavigation(
     ResourceResponse* response,
     std::unique_ptr<StreamHandle> body,
     const CommonNavigationParams& common_params,
     const RequestNavigationParams& request_params,
     bool is_view_source) {
   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);
 
   // Get back to a clean state, in case we start a new navigation without
   // completing an unload handler.
   ResetWaitingState();
 
   // The renderer can exit view source mode when any error or cancellation
   // happen. When reusing the same renderer, overwrite to recover the mode.
   if (is_view_source &&
       this == frame_tree_node_->render_manager()->current_frame_host()) {
     DCHECK(!GetParent());
     render_view_host()->Send(new FrameMsg_EnableViewSourceMode(routing_id_));
   }
 
   const GURL body_url = body.get() ? body->GetURL() : GURL();
   const ResourceResponseHead head = response ?
       response->head : ResourceResponseHead();
   Send(new FrameMsg_CommitNavigation(routing_id_, head, body_url, common_params,
                                      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.
   stream_handle_ = std::move(body);
 
   // When navigating to a debug url, no commit is expected from the
   // RenderFrameHost, nor should the throbber start. The NavigationRequest is
   // also not stored in the FrameTreeNode. Therefore do not reset it, as this
   // could cancel an existing pending navigation.
   if (!IsRendererDebugURL(common_params.url)) {
@@ skipping 654 matching lines @@
 }
 
 void RenderFrameHostImpl::OnMediaInterfaceFactoryConnectionError() {
   DCHECK(media_interface_proxy_);
   media_interface_proxy_.reset();
 }
 
 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,
     // which does not cause a NavigationHandle to be created because it does not
     // go through DidStartProvisionalLoad.
     bool is_renderer_initiated = true;
     int pending_nav_entry_id = 0;
     NavigationEntryImpl* pending_entry =
         NavigationEntryImpl::FromNavigationEntry(
             frame_tree_node()->navigator()->GetController()->GetPendingEntry());
@@ skipping 54 matching lines @@
   // There is no pending NavigationEntry in these cases, so pass 0 as the
   // pending_nav_entry_id. If the previous handle was a prematurely aborted
   // navigation loaded via LoadDataWithBaseURL, propagate the entry id.
   return NavigationHandleImpl::Create(
       params.url, frame_tree_node_, is_renderer_initiated,
       params.was_within_same_page, base::TimeTicks::Now(),
       entry_id_for_data_nav, false);  // started_from_context_menu
 }
 
 }  // namespace content