Report nav timing 2 instance as soon as it's requested.

third_party/WebKit/Source/core/timing/Performance.cpp

Index: third_party/WebKit/Source/core/timing/Performance.cpp
diff --git a/third_party/WebKit/Source/core/timing/Performance.cpp b/third_party/WebKit/Source/core/timing/Performance.cpp
index b5a7447cdce29c10697f4262a00d1ffec3e74041..1f361c2c02f15aaff047d531297ae5729e42af68 100644
--- a/third_party/WebKit/Source/core/timing/Performance.cpp
+++ b/third_party/WebKit/Source/core/timing/Performance.cpp
@@ -43,6 +43,7 @@
 #include "core/loader/DocumentLoader.h"
 #include "core/origin_trials/OriginTrials.h"
 #include "core/timing/PerformanceTiming.h"
+#include "platform/network/ResourceTimingInfo.h"
 
 static const double kLongTaskThreshold = 0.05;
 
@@ -140,6 +141,19 @@ PerformanceTiming* Performance::timing() const {
   return m_timing.get();
 }
 
+ResourceTimingInfo* Performance::getNavigationTimingInfo() const {

[Kunihiko Sakamoto, 2017/02/13 08:22:29]

It's probably better to just inline this function since it's only used
once.

[sunjian, 2017/02/14 21:29:03]

Done.

+  if (!frame())
+    return nullptr;
+  const DocumentLoader* documentLoader = frame()->loader().documentLoader();
+  DCHECK(documentLoader);
+  return documentLoader->getNavigationTimingInfo();
+}
+
+PerformanceNavigationTiming* Performance::createNavigationTimingInstance() {
+  return new PerformanceNavigationTiming(frame(), getNavigationTimingInfo(),
+                                         toTimeOrigin(frame()));

[Kunihiko Sakamoto, 2017/02/13 08:22:29]

You can just use timeOrigin().

[sunjian, 2017/02/14 21:29:03]

Done.

+}
+
 void Performance::updateLongTaskInstrumentation() {
   DCHECK(frame());
   if (!frame()->document() ||