Add DirectWrite flag and plumb it through to Blink

Add an "enable-direct-write" flag and plumb it through to
WebRuntimeFeatures on the Blink side.

[email protected]
BUG=25541

Review URL: https://codereview.chromium.org/66333016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239354 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 84a4250..3e644d08 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -451,6 +451,15 @@
     kOsWin,
     MULTI_VALUE_TYPE(kGDIPresentChoices)
   },
+#if defined(OS_WIN)
+  {
+    "enable-direct-write",
+    IDS_FLAGS_ENABLE_DIRECT_WRITE_NAME,
+    IDS_FLAGS_ENABLE_DIRECT_WRITE_DESCRIPTION,
+    kOsWin,
+    SINGLE_VALUE_TYPE(switches::kEnableDirectWrite)
+  },
+#endif
   {
     "enable-experimental-canvas-features",
     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_NAME,