[DO NOT COMMIT] Trace events for layout-based First Meaningful Paint detection

[DO NOT COMMIT] Trace events for layout-based First Meaningful Paint detection

- Logs LayoutAnalyzer trace event in blink.user_timing category (needed for WPT testing)
- Adds page and screen heights information to the trace event
- FontFaceSet::hasBlankText() checks there's any pending webfont in block period && >200 characters laid out

Design doc: https://docs.google.com/document/d/1BR94tJdZLsin5poeet0XoTW60M0SjvOJQttKT-JK8HI/edit?usp=sharing

[Kunihiko Sakamoto, 2016-04-12 05:44:38]

Description was changed from

==========
[DO NOT COMMIT] Logs layout stats as blink.user_timing trace events.

BUG=
==========

to

==========
[DO NOT COMMIT] Trace events for layout-based First Meaningful Paint detection

- Logs LayoutAnalyzer trace event in blink.user_timing category (needed for WPT
testing)
- Adds page and screen heights information to the trace event
- FontFaceSet::hasBlankText() checks there's any pending webfont in block period
&& >200 characters laid out
==========

[Kunihiko Sakamoto, 2016-04-26 08:52:24]

Description was changed from

==========
[DO NOT COMMIT] Trace events for layout-based First Meaningful Paint detection

- Logs LayoutAnalyzer trace event in blink.user_timing category (needed for WPT
testing)
- Adds page and screen heights information to the trace event
- FontFaceSet::hasBlankText() checks there's any pending webfont in block period
&& >200 characters laid out
==========

to

==========
[DO NOT COMMIT] Trace events for layout-based First Meaningful Paint detection

- Logs LayoutAnalyzer trace event in blink.user_timing category (needed for WPT
testing)
- Adds page and screen heights information to the trace event
- FontFaceSet::hasBlankText() checks there's any pending webfont in block period
&& >200 characters laid out

Design doc:
https://docs.google.com/document/d/1BR94tJdZLsin5poeet0XoTW60M0SjvOJQttKT-JK8...
==========

[paulirish, 2016-04-29 02:41:51]

https://codereview.chromium.org/1773633003/diff/160001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/frame/FrameView.cpp (right):

https://codereview.chromium.org/1773633003/diff/160001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/frame/FrameView.cpp:843:
value->setInteger("contentsHeightBefore", contentsSize().height());
Are you submitting a CL for these non-font counter values?

[Kunihiko Sakamoto, 2016-05-09 07:33:42]

https://codereview.chromium.org/1773633003/diff/160001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/frame/FrameView.cpp (right):

https://codereview.chromium.org/1773633003/diff/160001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/frame/FrameView.cpp:843:
value->setInteger("contentsHeightBefore", contentsSize().height());
On 2016/04/29 02:41:51, paulirish wrote:
> Are you submitting a CL for these non-font counter values?

Sorry for the delay, just sent out https://codereview.chromium.org/1957193002/
for review.