Share code between FontPlatformDataWin and FontPlatformDataHarfBuzz

Move linux specific code from FontPlatformDataHarfBuzz.cpp into a new
FontPlatformDataLinux.cpp file and merge the shared code across the win
and linux implementations into FontPlatformDataHarfBuzz.cpp.

With this change code shared across all HarfBuzz platforms is in
FontPlatformDataHarfBuzz.cpp and platform specific code in the Linux and
Windoows files respectively.

Once Mac is fully moved over to HarfBuzz FontPlatformDataHarfBuzz will
be renamed to FontPlatformData and moved to platform/fonts.

R=dglazkov@chromium.org

Review URL: https://codereview.chromium.org/214383007

git-svn-id: svn://svn.chromium.org/blink/trunk@170801 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update promote-img-in-viewport-priority with intra_priority output.

Also disabling the test until the chrome side lands, at which point I'll re-enable the test. Following suggestion from: https://codereview.chromium.org/220553002/


BUG=

Review URL: https://codereview.chromium.org/222553008

git-svn-id: svn://svn.chromium.org/blink/trunk@170802 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make HTMLInputElement.valueAsDate IDL match current spec.

Marking valueAsDate as nullable to match the current spec 
text. This change does not introduce any JavaScript visible
changes because the current double to Date conversion in
V8Binding.h returns null for all non-finite numbers.
This change sets the stage for allowing v8DateOrNull() to  
be changed to v8DateOrNaN() so that NaN dates can be returned.

BUG=359773
TEST=All existing LayoutTests pass.

Review URL: https://codereview.chromium.org/224523002

git-svn-id: svn://svn.chromium.org/blink/trunk@170803 bbb929c8-8fbe-4397-9dbb-9b2b20218538