PlzNavigate: identify same-page browser-initiated navigation.

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index 4ecd86acfe5d193b17657f2d080407ce30c033ae..7ff5135a46d297c8c0d79f390ed60e47472a4452 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -1183,6 +1183,12 @@ void FrameLoader::load(const FrameLoadRequest& passedRequest,
     return;
   }
 
+  // The navigation has not been detected to be same document. If the request
+  // was declared to be, it means that a renderer-side navigation occurs in
+  // between. In that case, this navigation is dropped.

[clamy, 2016/12/20 15:16:22]

Can you prefix the comment with // PlzNavigate ?
I would also rephrase it as the following:
// If the loader classifies this navigation as a different document navigation
while the browser intended the navigation to be same-document, drop the
navigation. A different navigation must have committed while the IPC was sent.

[arthursonzogni, 2016/12/21 10:11:08]

Done.

+  if (request.resourceRequest().isSameDocumentNavigation())
+    return;
+
   startLoad(request, newLoadType, policy);
 }