PlzNavigate: ensure POST navigations are treated as different document

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 24b4a63d43c5123611eee2045d8400145599a277..1fda4abd62b58b4b972b3b2f0690f31ebe334c2e 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -1514,7 +1514,7 @@ bool FrameLoader::shouldPerformFragmentNavigation(bool isFormSubmission,
   // We don't do this if we are submitting a form with method other than "GET",
   // explicitly reloading, currently displaying a frameset, or if the URL does
   // not have a fragment.
-  return (!isFormSubmission || equalIgnoringCase(httpMethod, HTTPNames::GET)) &&
+  return equalIgnoringCase(httpMethod, HTTPNames::GET) &&
          !isReloadLoadType(loadType) && loadType != FrameLoadTypeBackForward &&
          url.hasFragmentIdentifier() &&
          equalIgnoringFragmentIdentifier(m_frame->document()->url(), url)