Always use skia text rendering on Windows in Aura. GDI rendering is really wonky, and this is a convenient fix.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/8400023

git-svn-id: http://src.chromium.org/svn/trunk/src/build@107608 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -285,6 +285,12 @@
           'toolkit_uses_gtk%': 1,
           'use_x11%': 1,
         }],
+        # We always use skia text rendering in Aura on Windows, since GDI
+        # doesn't agree with our BackingStore.
+        # TODO(beng): remove once skia text rendering is on by default.
+        ['use_aura==1 and OS=="win"', {
+          'enable_skia_text%': 1,
+        }],
         ['use_aura==1 and OS!="win"', {
           'toolkit_uses_gtk%': 0,
         }],