Support OpenType GSUB lookupType 7 and substFormat 1

They are used in Android's DroidSansFallback.ttf. Missing the support
will cause punctuations in vertical text incorrectly rotated.

The change is according to the following spec:
http://partners.adobe.com/public/developer/opentype/index_table_formats1.html

BUG=287995
TEST=Push LayoutTests/fast/writing-mode/vertical-subst-vertical-subst-font-vert-no-dflt.html onto device and open it from Chrome (it will use the system DroidSansFallback.ttf). The punctuations should be in correct orientation.

Review URL: https://chromiumcodereview.appspot.com/23973004

git-svn-id: svn://svn.chromium.org/blink/trunk@157737 bbb929c8-8fbe-4397-9dbb-9b2b20218538