Timeline: avoid exception when there's no closing Layout record

A bunch of layout tests used to flake with "Uncaught exception in
inspector front-end: Uncaught TypeError: Cannot read property 'rootNode'
of undefined". This is apparently due to the fact that the trace is
stopped while Layout is in progress, hence we do not get the closing
record and fail upon an attempt to access event.args["endData"]

Review URL: https://codereview.chromium.org/626483004

git-svn-id: svn://svn.chromium.org/blink/trunk@183136 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: trim popover text displayed in object popover

A very long text in popover is rendered way too long. This patch trims
end of the string if its lenght exceeds 10000 chars.

BUG=419666
R=aandrey, vsevik

Review URL: https://codereview.chromium.org/615853005

git-svn-id: svn://svn.chromium.org/blink/trunk@183137 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove obsolete Mac specific code from SimpleFontData

Remove a bunch of Mac specific code from SimpleFontData that is no
longer used since the switch to HarfBuzz.

BUG=286450
R=dominik.rottsches@intel.com

Review URL: https://codereview.chromium.org/621983004

git-svn-id: svn://svn.chromium.org/blink/trunk@183138 bbb929c8-8fbe-4397-9dbb-9b2b20218538