Add texture compression utility

R=robertphillips@google.com, egdaniel@google.com, halcanary@google.com, scroggo@google.com, reed@google.com

Author: krajcevski@google.com

Review URL: https://codereview.chromium.org/325733004
diff --git a/gyp/utils.gypi b/gyp/utils.gypi
index 3a94cc3..3097446 100644
--- a/gyp/utils.gypi
+++ b/gyp/utils.gypi
@@ -83,6 +83,8 @@
         '<(skia_src_path)/utils/SkSHA1.cpp',
         '<(skia_src_path)/utils/SkSHA1.h',
         '<(skia_src_path)/utils/SkRTConf.cpp',
+        '<(skia_src_path)/utils/SkTextureCompressor.cpp',
+        '<(skia_src_path)/utils/SkTextureCompressor.h',
         '<(skia_src_path)/utils/SkThreadUtils.h',
         '<(skia_src_path)/utils/SkThreadUtils_pthread.cpp',
         '<(skia_src_path)/utils/SkThreadUtils_pthread.h',