Add initial Chromium TestShell support for Android

Add a build target and tie it into android_all.  This will build and link
Chrome code for a test apk for Android.  When it runs it properly
loads the library but crashes.  Will fix the crashes in subsequent
patches, but can fork that work after this is in.

BUG=136786


Review URL: https://chromiumcodereview.appspot.com/10918113

git-svn-id: http://src.chromium.org/svn/trunk/src/build@155950 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

all_android.gyp

@@ -21,6 +21,7 @@
         '../content/content.gyp:content_shell_apk',
         '<@(android_app_targets)',
         'android_builder_tests',
+        '../chrome/chrome.gyp:chromium_testshell'
       ],
     }, # target_name: All
     {