The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/59250b64593759462cdefbf4f411f1cca6e0c696

commit 59250b64593759462cdefbf4f411f1cca6e0c696
Author: sunjian <sunjian@chromium.org>
Date: Fri Jan 13 01:43:14 2017

fixed encodedBodySize/decodedBodySize/initiatorType for nav timing 2. Report initiatorType as "navigation" instead of an empty string.

BUG= 675044 , 675042 

Review-Url: https://codereview.chromium.org/2582863002
Cr-Commit-Position: refs/heads/master@{#443445}

[modify] https://crrev.com/59250b64593759462cdefbf4f411f1cca6e0c696/third_party/WebKit/LayoutTests/http/tests/w3c/webperf/approved/navigation-timing/html/nav2_test_attributes_values.html
[modify] https://crrev.com/59250b64593759462cdefbf4f411f1cca6e0c696/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
[modify] https://crrev.com/59250b64593759462cdefbf4f411f1cca6e0c696/third_party/WebKit/Source/core/timing/PerformanceBase.cpp
[modify] https://crrev.com/59250b64593759462cdefbf4f411f1cca6e0c696/third_party/WebKit/Source/core/timing/PerformanceNavigationTiming.cpp