PlzNavigate: identify same-page browser-initiated navigation.

content/browser/frame_host/navigation_request.cc

 // Copyright 2014 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/navigation_request.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "content/browser/appcache/appcache_navigation_handle.h"
@@ skipping 202 matching lines @@
   base::Optional<url::Origin> initiator =
       frame_tree_node->IsMainFrame()
           ? base::Optional<url::Origin>()
           : base::Optional<url::Origin>(
                 frame_tree_node->frame_tree()->root()->current_origin());
 
   // While the navigation was started via the LoadURL path it may have come from
   // the renderer in the first place as part of OpenURL.
   bool browser_initiated = !entry.is_renderer_initiated();
 
+  bool is_history_navigation = frame_entry.page_state().IsValid();
+
+  // A same-document fragment-navigation happens when the only part of the url
+  // that is modified is after the '#' character.
+  // Be careful not to consider history navigations. For instance, if the
+  // history is: 'A#bar' -> 'B' -> 'A#foo'. Then an history navigation from
+  // 'A#foo' to 'A#bar' is not a same-document navigation, but a
+  // different-document one! The two FrameNavigationEntry doesn't share the same
+  // document_sequence_number.
+  bool is_same_document_fragment_change =
+      net::IsFragmentAddedOrUpdated(frame_tree_node->current_url(), dest_url) &&
+      !is_history_navigation;

[nasko, 2017/01/13 19:36:57]

Thanks for the comment! I was discussing this logic with creis@ and he pointed
out that we should be matching here the logic that Blink uses to determine the
same type of navigation. Looking at
FrameLoader::shouldPerformFragmentNavigation, it does a few extra checks, which
we should ensure we match.

Brings up another question - even if we have a history navigation, we might not
need to make the network request. Assume we go from "a.com/#bar" to
"a.com/#foo", it will be a is_same_document_history_load and we need to ensure
we handle this too.

[arthursonzogni, 2017/01/17 15:24:47]

Thanks for shouldPerformFragmentNavigation. I will try to do a function like
this in the navigation_request.

Concerning your other question, I don't understand what is the problem.
In that case we will get : 
is_same_document_fragment_change == false;
is_same_document_history_load    == true;
And since NavigationHandle::IsSamePage() is true when one of the last two
booleans are true, no network request will be made.

+
   std::unique_ptr<NavigationRequest> navigation_request(new NavigationRequest(
       frame_tree_node, entry.ConstructCommonNavigationParams(
                            frame_entry, request_body, dest_url, dest_referrer,
                            navigation_type, previews_state, navigation_start),
       BeginNavigationParams(entry.extra_headers(), net::LOAD_NORMAL,
                             false,  // has_user_gestures
                             false,  // skip_service_worker
                             REQUEST_CONTEXT_TYPE_LOCATION,
                             blink::WebMixedContentContextType::Blockable,
                             initiator),
       entry.ConstructRequestNavigationParams(
-          frame_entry, is_same_document_history_load,
-          is_history_navigation_in_new_child,
+          frame_entry, is_same_document_fragment_change,
+          is_same_document_history_load, is_history_navigation_in_new_child,
           entry.GetSubframeUniqueNames(frame_tree_node),
           frame_tree_node->has_committed_real_load(),
           controller->GetPendingEntryIndex() == -1,
           controller->GetIndexOfEntry(&entry),
           controller->GetLastCommittedEntryIndex(),
           controller->GetEntryCount()),
       browser_initiated,
       true,  // may_transfer
       &frame_entry, &entry));
   return navigation_request;
 }
 
 // static
 std::unique_ptr<NavigationRequest> NavigationRequest::CreateRendererInitiated(
     FrameTreeNode* frame_tree_node,
     const CommonNavigationParams& common_params,
     const BeginNavigationParams& begin_params,
     int current_history_list_offset,
     int current_history_list_length) {
-  // TODO(clamy): Check if some PageState should be provided here.
+
+  // No renderer-initiated same-document navigation are using this method. The
+  // navigation takes place in the renderer without asking the browser to
+  // navigate.
+  DCHECK(net::IsFragmentAddedOrUpdated(frame_tree_node->current_url(),
+                                       common_params.url));
+
+  // Please note that no history-navigation uses this method as well.

[nasko, 2017/01/13 19:36:57]

nit: Put the comments together before the DCHECK. You can put this one first, if
you want to ensure the other ones is closer to the DCHECK.

+
   // TODO(clamy): See how we should handle override of the user agent when the
   // navigation may start in a renderer and commit in another one.
   // TODO(clamy): See if the navigation start time should be measured in the
   // renderer and sent to the browser instead of being measured here.
   // TODO(clamy): The pending history list offset should be properly set.
   RequestNavigationParams request_params(
-      false,                   // is_overriding_user_agent
-      std::vector<GURL>(),     // redirects
-      false,                   // can_load_local_resources
-      PageState(),             // page_state
-      0,                       // nav_entry_id
-      false,                   // is_same_document_history_load
-      false,                   // is_history_navigation_in_new_child
-      std::map<std::string, bool>(), // subframe_unique_names
+      false,                          // is_overriding_user_agent
+      std::vector<GURL>(),            // redirects
+      false,                          // can_load_local_resources
+      PageState(),                    // page_state
+      0,                              // nav_entry_id
+      false,                          // is_same_document_fragment_change
+      false,                          // is_same_document_history_load
+      false,                          // is_history_navigation_in_new_child
+      std::map<std::string, bool>(),  // subframe_unique_names
       frame_tree_node->has_committed_real_load(),
-      false,                   // intended_as_new_entry
-      -1,                      // pending_history_list_offset
+      false,  // intended_as_new_entry
+      -1,     // pending_history_list_offset
       current_history_list_offset, current_history_list_length,
-      false,                   // is_view_source
-      false,                   // should_clear_history_list
+      false,  // is_view_source
+      false,  // should_clear_history_list
       begin_params.has_user_gesture);
-  std::unique_ptr<NavigationRequest> navigation_request(
-      new NavigationRequest(frame_tree_node, common_params, begin_params,
-                            request_params,
-                            false, // browser_initiated
-                            false, // may_transfer
-                            nullptr, nullptr));
+  std::unique_ptr<NavigationRequest> navigation_request(new NavigationRequest(
+      frame_tree_node, common_params, begin_params, request_params,
+      false,  // browser_initiated
+      false,  // may_transfer
+      nullptr, nullptr));
   return navigation_request;
 }
 
 NavigationRequest::NavigationRequest(
     FrameTreeNode* frame_tree_node,
     const CommonNavigationParams& common_params,
     const BeginNavigationParams& begin_params,
     const RequestNavigationParams& request_params,
     bool browser_initiated,
     bool may_transfer,
@@ skipping 46 matching lines @@
 
 NavigationRequest::~NavigationRequest() {
 }
 
 void NavigationRequest::BeginNavigation() {
   DCHECK(!loader_);
   DCHECK(state_ == NOT_STARTED || state_ == WAITING_FOR_RENDERER_RESPONSE);
   state_ = STARTED;
   RenderFrameDevToolsAgentHost::OnBeforeNavigation(navigation_handle_.get());
 
-  if (ShouldMakeNetworkRequestForURL(common_params_.url)) {
+  if (ShouldMakeNetworkRequestForURL(common_params_.url) &&
+      !navigation_handle_->IsSamePage()) {
     // It's safe to use base::Unretained because this NavigationRequest owns
     // the NavigationHandle where the callback will be stored.
     // TODO(clamy): pass the real value for |is_external_protocol| if needed.
     // TODO(clamy): pass the method to the NavigationHandle instead of a
     // boolean.
     navigation_handle_->WillStartRequest(
         common_params_.method, common_params_.post_data,
         Referrer::SanitizeForRequest(common_params_.url,
                                      common_params_.referrer),
         begin_params_.has_user_gesture, common_params_.transition, false,
@@ skipping 14 matching lines @@
   NavigatorImpl::CheckWebUIRendererDoesNotDisplayNormalURL(render_frame_host,
                                                            common_params_.url);
 
   // Inform the NavigationHandle that the navigation will commit.
   navigation_handle_->ReadyToCommitNavigation(render_frame_host);
 
   CommitNavigation();
 }
 
 void NavigationRequest::CreateNavigationHandle(int pending_nav_entry_id) {
-  // TODO(nasko): Update the NavigationHandle creation to ensure that the
-  // proper values are specified for is_same_page.
+  bool is_same_page = request_params_.is_same_document_fragment_change ||
+                      request_params_.is_same_document_history_load;
+
   navigation_handle_ = NavigationHandleImpl::Create(
-      common_params_.url, frame_tree_node_, !browser_initiated_,
-      false,  // is_same_page
+      common_params_.url, frame_tree_node_, !browser_initiated_, is_same_page,
       common_params_.navigation_start, pending_nav_entry_id,
       false);  // started_in_context_menu
 
   if (!begin_params_.searchable_form_url.is_empty()) {
     navigation_handle_->set_searchable_form_url(
         begin_params_.searchable_form_url);
     navigation_handle_->set_searchable_form_encoding(
         begin_params_.searchable_form_encoding);
   }
 }
@@ skipping 291 matching lines @@
   // Have the processing of the response resume in the network stack.
   loader_->ProceedWithResponse();
 
   CommitNavigation();
 
   // DO NOT ADD CODE after this. The previous call to CommitNavigation caused
   // the destruction of the NavigationRequest.
 }
 
 void NavigationRequest::CommitNavigation() {
-  DCHECK(response_ || !ShouldMakeNetworkRequestForURL(common_params_.url));
+  DCHECK(response_ || !ShouldMakeNetworkRequestForURL(common_params_.url) ||
+         navigation_handle_->IsSamePage());
   DCHECK(!common_params_.url.SchemeIs(url::kJavaScriptScheme));
 
   // Retrieve the RenderFrameHost that needs to commit the navigation.
   RenderFrameHostImpl* render_frame_host =
       navigation_handle_->GetRenderFrameHost();
   DCHECK(render_frame_host ==
              frame_tree_node_->render_manager()->current_frame_host() ||
          render_frame_host ==
              frame_tree_node_->render_manager()->speculative_frame_host());
 
   TransferNavigationHandleOwnership(render_frame_host);
 
   DCHECK_EQ(request_params_.has_user_gesture, begin_params_.has_user_gesture);
 
   render_frame_host->CommitNavigation(response_.get(), std::move(body_),
                                       common_params_, request_params_,
                                       is_view_source_);
 
   frame_tree_node_->ResetNavigationRequest(true);
 }
 
 }  // namespace content