Add on-by-default tracing to FrameView::invalidateTree which adds more debug info

Add on-by-default tracing to FrameView::invalidateTree which adds more debug info
if the tracing category blink.invalidation is on.
BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=175831

[ojan, 2014-06-07 02:17:23]

Thinking about this more, I'm really skeptical that this will be too expensive
to just always do. I believe it matters for the recursive calls, but we only
call this method once per layout, no?

[esprehn, 2014-06-07 02:20:40]

https://codereview.chromium.org/320553004/diff/1/Source/core/frame/FrameView.cpp
File Source/core/frame/FrameView.cpp (right):

https://codereview.chromium.org/320553004/diff/1/Source/core/frame/FrameView....
Source/core/frame/FrameView.cpp:1049: debugData =
root->debugName().ascii().data();
All you're trying to do is save the one virtual call and the malloc for the
string here?

Also I don't think this is correct, the CString that created in ascii() will be
free by the time you get to the trace event below which should result in
crashes. You'd need to store the CString in a local.

[chrishtr, 2014-06-09 20:05:02]

Ok I went with the simple version.

[ojan, 2014-06-09 21:54:59]

lgtm

[commit-bot: I haz the power, 2014-06-09 21:55:19]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/chrishtr@chromium.org/320553004/40001

[commit-bot: I haz the power, 2014-06-09 23:04:12]

Change committed as 175831