Add non power of two gm for ETC1 bitmap

R=robertphillips@google.com

Author: krajcevski@google.com

Review URL: https://codereview.chromium.org/316813005
diff --git a/gyp/SampleApp.gyp b/gyp/SampleApp.gyp
index e0579ac..b15fd2d 100644
--- a/gyp/SampleApp.gyp
+++ b/gyp/SampleApp.gyp
@@ -149,6 +149,7 @@
         'pdf.gyp:pdf',
         'views_animated.gyp:views_animated',
         'lua.gyp:lua',
+        'etc1.gyp:libetc1',
       ],
      'conditions' : [
        [ 'sample_pdf_file_viewer == 1', {