[Android] Use mb on chromium.linux and tryserver.chromium.android.

scripts/slave/recipe_modules/chromium/example.expected/basic_out_dir.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "chromium.linux",
       "--builder",
       "Android Builder (dbg)",
@@ skipping 114 matching lines @@
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
+      "GYP_CHROMIUM_NO_ACTION": "1",

[Dirk Pranke, 2016/03/09 19:55:49]

Ick, the example.py in recipe_modules/chromium depends on chromium_tests? That's
a bad example ... :(.

[martiniss, 2016/03/09 19:58:10]

:(

       "GYP_CROSSCOMPILE": "1",
       "GYP_DEFINES": "OS=android component=static_library fastbuild=1 ffmpeg_branding=Chrome gomadir='[SLAVE_BUILD]/src/build/goma/client' proprietary_codecs=1 target_arch=arm test_isolation_mode=prepare use_goma=1",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s:RECIPE_PACKAGE[depot_tools]"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
@@ skipping 63 matching lines @@
       "@@@STEP_LOG_LINE@json.output (invalid)@null@@@",
       "@@@STEP_LOG_END@json.output (invalid)@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]