Turn on the picture runtime flag by default

Following the discussion on the "intent to ship" thread (https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/t3KRycUCGA8/VTJMRx20XiwJ ), this CL turns the flag on by default.

BUG=368830

Review URL: https://codereview.chromium.org/401403003

git-svn-id: svn://svn.chromium.org/blink/trunk@178754 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Implement CSSOM View smooth scroll for Window.{scroll, scrollTo, scrollBy}

This implements smooth scrolling for scroll(), scrollTo(), and scrollBy()
on main frames and subframes.

Smooth scrolling for Elements (that is, for setting scrollTop and scrollLeft
or calling scrollIntoView) will be added in later CLs.

For now, all scroll animations are performed on the main-thread. The use
of compositor-driven animations (for ScrollableAreas that have
compositor-driven scrolling) will be added in a later CL.

Intent-to-implement: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/YLWs9N46XjQ

Spec: http://www.w3.org/TR/cssom-view/

BUG=243871

Review URL: https://codereview.chromium.org/384973003

git-svn-id: svn://svn.chromium.org/blink/trunk@178755 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove QuickTime classid quirk.

This is a non-standard site-specific quirk for Mac OS X Wiki Server.
And NPAPI is going away soon anyway.

This was added three years ago in WebKit:
https://bugs.webkit.org/show_bug.cgi?id=61229

BUG=396290

Review URL: https://codereview.chromium.org/414443006

git-svn-id: svn://svn.chromium.org/blink/trunk@178756 bbb929c8-8fbe-4397-9dbb-9b2b20218538