transferSize implementation

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

Index: third_party/WebKit/Source/core/loader/DocumentLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
index ba90b82aa70e5e3e32e3a4f5ed2fca29cdde0e33..a978ba0fdc0ba547e0e20b21aeabbe14e79da404 100644
--- a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
@@ -107,6 +107,7 @@ DocumentLoader::DocumentLoader(LocalFrame* frame,
                          ClientRedirectPolicy::ClientRedirect),
       m_replacesCurrentHistoryItem(false),
       m_dataReceived(false),
+      m_mainResourceIdentifier(0),
       m_navigationType(NavigationTypeOther),
       m_documentLoadTiming(*this),
       m_timeOfLastDataReceived(0.0),
@@ -145,7 +146,11 @@ DEFINE_TRACE(DocumentLoader) {
 }
 
 unsigned long DocumentLoader::mainResourceIdentifier() const {
-  return m_mainResource ? m_mainResource->identifier() : 0;
+  return m_mainResourceIdentifier;

[Yoav Weiss, 2016/11/29 10:39:32]

Why do we need to store this rather than get the identifier from m_mainResource
as before? Did you see issues related to that?

[sunjian, 2016/11/29 19:33:30]

Yeah, m_mainResource gets reset to nullptr after in clearMainResourceHandle()
after notifyFinished(Resource* resource) gets called. The
mainResourceIdentifier() method was used for logging purpose when they decide
not to continue loading (something went wrong) which will not cause
m_mainResource gets cleared. But when loading finished (success or failure),
they decided that they no longer need to hold on to this object any more. 

+}
+
+ResourceTimingInfo* DocumentLoader::getMainResourceTimingInfo() const {
+  return fetcher()->getMainResourceTimingInfo(mainResourceIdentifier());
 }
 
 const ResourceRequest& DocumentLoader::originalRequest() const {
@@ -717,6 +722,7 @@ void DocumentLoader::startLoadingMainResource() {
                             mainResourceLoadOptions);
   m_mainResource =
       RawResource::fetchMainResource(fetchRequest, fetcher(), m_substituteData);
+  m_mainResourceIdentifier = m_mainResource ? m_mainResource->identifier() : 0;
 
   // PlzNavigate:
   // The final access checks are still performed here, potentially rejecting