GYP Changes and Scripts for Compiling Skia for ChromeOS

For now, this requires having a complete ChromeOS checkout.

R=djsollen@google.com

Review URL: https://codereview.chromium.org/16099011

git-svn-id: http://skia.googlecode.com/svn/trunk@9505 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/DEPS b/DEPS
index ddc7593..f140f0f 100644
--- a/DEPS
+++ b/DEPS
@@ -27,6 +27,9 @@
     "platform_tools/android/third_party/externals/png" : "https://android.googlesource.com/platform/external/libpng.git@android-4.2.2_r1.2",
     "platform_tools/android/third_party/externals/jpeg" : "https://android.googlesource.com/platform/external/jpeg.git@android-4.2.2_r1.2",
   },
+  "chromeos": {
+    "platform_tools/chromeos/third_party/externals/gif" : "https://android.googlesource.com/platform/external/giflib.git@android-4.2.2_r1.2",
+  },
 }
 
 #hooks = [