Fix some references to Makefiles in gyp_skia.

BUG=None
TEST=None, no functional changes. Just updating documentation.
R=epoger@google.com

Review URL: https://codereview.chromium.org/263083006

git-svn-id: http://skia.googlecode.com/svn/trunk@14642 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp_skia b/gyp_skia
index 20bfd79..151fa7b 100755
--- a/gyp_skia
+++ b/gyp_skia
@@ -54,10 +54,8 @@
 
   return result
 
-# Return the directory where all generated files (including Makefiles) are to
-# be written.
+# Return the directory where all the build files are to be written.
 def get_output_dir():
-
   # SKIA_OUT can be any directory either as a child of the standard out/
   # directory or any given location on the file system (e.g. /tmp/skia)
   output_dir = os.getenv('SKIA_OUT')
@@ -119,10 +117,10 @@
   args.extend(['-I' + i for i in additional_include_files(args)])
   args.extend(['--depth', '.'])
 
-  # Tell gyp to write the Makefiles into output_dir
+  # Tell gyp to write the build files into output_dir.
   args.extend(['--generator-output', os.path.abspath(get_output_dir())])
 
-  # Tell make to write its output into the same dir
+  # Tell ninja to write its output into the same directory.
   args.extend(['-Goutput_dir=.'])
 
   # By default, we build 'most' instead of 'all' or 'everything'. See skia.gyp.