Add support for WebFont sub-css-pixel font sizes

Add support for sub-css-pixel font sizes for web fonts when the
SubpixelFontScaling feature is enabled.

Covered by http://blink.gs/tests/text-scaling/webfont.html, will add
as a LayoutTest once supported on all platforms.

R=leviw@chromium.org
BUG=290411

Review URL: https://codereview.chromium.org/25638008

git-svn-id: svn://svn.chromium.org/blink/trunk@158945 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[Android WebView] Simplify processing of initial-scale=0 with viewportMetaZeroValuesQuirk

It turns out that we can always treat zero initial-scale as 'auto'.
The previous logic has been copied from the current implementation,
but as experiments show, the resulting layout parameters are also
compatible with the existing implementation even with this simplified
logic.

BUG=282130

Review URL: https://codereview.chromium.org/25749002

git-svn-id: svn://svn.chromium.org/blink/trunk@158946 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rebaselines for r158867.

The auto-rebaseline in r158867 didn't quite work for all tests,
manually update a couple of the results.

TBR=leviw@chromium.org

Merge branch 'master' of https://chromium.googlesource.com/chromium/blink into rebase

Manual windows rebaselines for r158845.

TBR=leviw@chromium.org
BUG=

Review URL: https://codereview.chromium.org/25892009

git-svn-id: svn://svn.chromium.org/blink/trunk@158947 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move TextBreakIterator*.cpp/.h to Source/platform/text/

BUG=297477

Review URL: https://codereview.chromium.org/25884002

git-svn-id: svn://svn.chromium.org/blink/trunk@158948 bbb929c8-8fbe-4397-9dbb-9b2b20218538