Additional cleanups to Android config parsing.

platform_tools/android/gyp/dependencies.gypi

 # This GYP file stores the dependencies necessary to build Skia on the Android
 # platform. The OS doesn't provide many stable libraries as part of the
 # distribution so we have to build a few of them ourselves.
 #
 # NOTE: We tried adding the gyp file to the android/ directory at the root of
 # the Skia repo, but that resulted in the generated makefiles being created
 # outside of the out directory. We may be able to move the bulk of this gyp
 # to the /android directory and put a simple shim here, but that has yet to be
 # tested.
 
@@ skipping 26 matching lines @@
         '../third_party/externals/expat/lib/xmlrole.c',
         '../third_party/externals/expat/lib/xmltok.c',
       ],
       'include_dirs': [
         '../third_party/externals/expat',
         '../third_party/externals/expat/lib',
       ],
       'cflags': [
         '-w',
         '-fexceptions',
-        '-DHAVE_EXPAT_CONFIG_H',
+      ],
+      'defines': [
+        'HAVE_EXPAT_CONFIG_H',

[scroggo, 2015/02/10 13:59:41]

IIRC, the difference here is that defines will get put in SkUserConfig, which is
our hacky way of exporting compile flags. Is that the intent here?

[scroggo, 2015/02/10 15:11:26]

Discussed this in person:
I was referring to the Android framework build, which this does not affect.

Ben actually wanted it to show up in his IDE (or some other tool) as a define,
which this allows.

Back to the Android framework build, perhaps a better method would be to be more
explicit, and list defines we want to export in export_dependent_settings (which
may be all of them?). This will probably be necessary anyway once the Android
build system starts supporting exported flags. I've filed skbug.com/3415 to
track that.

[bungeman-skia, 2015/02/10 15:34:11]

So the idea was to just have all the defines in 'defines' which makes it easier
in my editor (since it's looking at the 'defines' for defines) to see which
macros are defined so that my editor can say, for example, which code is live
and which is defined out. This came up with expat, as it will behave quite
differently if XML_CONTEXT_BYTES isn't defined.

Turns out after discussion that this target is only used by Skia tool builds and
is skipped by the Android makefile generation, so this shouldn't make a
difference there.

       ],
       'direct_dependent_settings': {
         'include_dirs': [
           '../third_party/externals/expat/lib',  # For expat.h
         ],
       }
     },
     {
       'target_name': 'gif',
       'type': 'static_library',
@@ skipping 175 matching lines @@
           }],
         ],
         'sources': [
           '../app/jni/com_skia_SkiaSampleRenderer.cpp',
         ],
       },
 
     },
   ]
 }