Additional cleanups to Android config parsing.

platform_tools/android/gyp/dependencies.gypi

Index: platform_tools/android/gyp/dependencies.gypi
diff --git a/platform_tools/android/gyp/dependencies.gypi b/platform_tools/android/gyp/dependencies.gypi
index bb0db7184bbc8e2d2cb822002609c634e27b221e..6507ee45f742f6dbd6ebce160217eaddb8c76df0 100644
--- a/platform_tools/android/gyp/dependencies.gypi
+++ b/platform_tools/android/gyp/dependencies.gypi
@@ -44,7 +44,9 @@
       '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': [