Remove the autosizing modes in favor of a dev site link.

Per discussion on http://crbug.com/319092, the autosizing configurations
are going to be confusing to users. This change switches back to just
a single "text autosizing" checkbox that emulates Chrome on Android's
text autosizing behavior. This change also adds a link at the bottom of the
screen emulation page for more information on the developers.google.com site.

A followup patch will add help icons next to some of the checkboxes for
light-weight contextual information.

Preview screenshot: http://pr.gg/devsitelink.png

BUG=319092

Review URL: https://codereview.chromium.org/77723002

git-svn-id: svn://svn.chromium.org/blink/trunk@163062 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Track number of RefCounted object instances.

This patch introduces InstanceCounter class to keep map<classname, counter>. The counter is incremented/decremented from RefCounted c-tor/d-tor. As RTTI is not available in Blink, we use output from __PRETTY_FUNCTION__ macro to stringify typename from a template parameter T.

Internals::dumpRefCountedInstanceCounts() API is provided to get results. This is to be used from the Blink Leak Detector.

with patch: binary size: 886M out/Debug/lib/libwebkit.so
            time run_webkit_tests --debug: 721.32s user 284.36s system 156% cpu 10:44.45 total

without patch: binary size: 882M out/Debug/lib/libwebkit.so
            time run_webkit_tests --debug: 710.66s user 279.06s system 182% cpu 9:01.73 total

Review URL: https://codereview.chromium.org/94343002

git-svn-id: svn://svn.chromium.org/blink/trunk@163063 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Override hasPendingActivity() instead of using set/unsetPendingActivity() methods.

Asynchronous dropProtection is also removed since now events are not
dispatched inside stop().

BUG=none

Review URL: https://codereview.chromium.org/80473002

git-svn-id: svn://svn.chromium.org/blink/trunk@163064 bbb929c8-8fbe-4397-9dbb-9b2b20218538
In https://codereview.chromium.org/38793007 and
https://codereview.chromium.org/40423003 I added new flags for enabling
the viewport meta tag. Currently, these flags aren't hooked-up to the
actual setting values yet since that would have broken numerous tests.
This CL adds the necessary flag settings to unit tests so the flags can
be enabled.

BUG=232102

Review URL: https://codereview.chromium.org/99493003

git-svn-id: svn://svn.chromium.org/blink/trunk@163065 bbb929c8-8fbe-4397-9dbb-9b2b20218538