Reland "Gyp file changes for the android framework."

gyp/zlib.gyp

+# Target for including zlib.
 {
   'targets': [
     {
       'target_name': 'zlib',
       'type': 'static_library',
       'dependencies': [
         'skia_lib.gyp:skia_lib',
       ],
       'sources': [
         '../include/core/SkFlate.h',
@@ skipping 12 matching lines @@
         [ 'skia_os == "ios"', {
           'link_settings': {
             'libraries': [
               '$(SDKROOT)/usr/lib/libz.dylib',
             ],
           },
           'defines': [ 'SK_ZLIB_INCLUDE=<zlib.h>', ],
         }],
         [ 'skia_os in ["linux", "freebsd", "openbsd", "solaris", "android", "nacl"]', {
           'link_settings': { 'libraries': [ '-lz', ], },
-          'defines': [ 'SK_ZLIB_INCLUDE=<zlib.h>', ],
+          'conditions': [
+            [ 'skia_android_framework==0', {
+              'defines': [ 'SK_ZLIB_INCLUDE=<zlib.h>', ],
+            }],
+          ],
+        }],
+        [ 'skia_android_framework', {
+          'include_dirs': [
+            'external/zlib',
+          ],
         }],
       ],
     },
   ],
 }