Reland r179231 with oilpan build fixes

VC++ doesn't support Empty Base Class Optimization. This CL adds CSSValueBaseAsEBCO as a workaround to avoid the bloat of instance size of CSSValue. For details see the comment in CSSValue.h.

We enable CSSValueBaseAsEBCO only in MSVC because enabling CSSValueBaseAsEBCO in clang causes an error of the GC plugin. See discussion in https://codereview.chromium.org/429283002/ for more details.

Review URL: https://codereview.chromium.org/426333003

git-svn-id: svn://svn.chromium.org/blink/trunk@179402 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark tests for rebaseline after SK_IGNORE_QUAD_RR_CORNERS_OPT removal.

Unreviewed gardening.

TBR=robertphillips@google.com
BUG=309611

Review URL: https://codereview.chromium.org/435983002

git-svn-id: svn://svn.chromium.org/blink/trunk@179403 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Do not focus the remove button in settings list.

BUG=340219

Review URL: https://codereview.chromium.org/434863002

git-svn-id: svn://svn.chromium.org/blink/trunk@179404 bbb929c8-8fbe-4397-9dbb-9b2b20218538