Add fontconfig to linux DEPS for embedded builds (reland)

We'll use this in-tree fontconfig when "embedded=1" is set in GYP_DEFINES.

This was reverted pending license checker changes (landed as r127213003).

Relanding with the following changes from the third_party HOWTO:
  - Added OWNERS file
  - Updated .gitignore

BUG=318315

Review URL: https://codereview.chromium.org/133903005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244318 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/DEPS b/DEPS
index 1f44577b..2d863562 100644
--- a/DEPS
+++ b/DEPS
@@ -495,6 +495,10 @@
       Var("chromium_git") +
       "/external/liblouis.git@3c2daee56250162e5a75830871601d74328d39f5",
 
+    # Used for embedded builds. CrOS & Linux use the system version.
+    "src/third_party/fontconfig/src":
+      Var("chromium_git") + "/external/fontconfig.git" +
+      "@4f944971dac3c0bbc6fdd3bf3123e3c8378a3acb",
   },
   "android": {
     "src/third_party/android_tools":