Store GPU pixel test reference images outside source tree

Instead of keeping the Android GPU pixel test reference images inside
the source tree, store them under the top level build bot directory,
e.g.,
/b/build/slave/<slave_name>/build/content_gpu_data/telemetry/{gpu_reference,generated}

This matches the location used on the non-Android GPU bots.

This patch also gives the current SVN revision to the test runner so the
reference images will get updated correctly.

TBR=navabi@chromium.org

Review URL: https://codereview.chromium.org/105183002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@240338 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/buildbot/bb_device_steps.py

@@ -451,8 +451,14 @@ def RunGPUTests(options):
   InstallApk(options, INSTRUMENTATION_TESTS['ContentShell'], False)
 
   bb_annotations.PrintNamedStep('gpu_tests')
+  revision = _GetRevision(options)
+  data_dir = os.path.join(DIR_BUILD_ROOT, 'content_gpu_data', 'telemetry')
   RunCmd(['content/test/gpu/run_gpu_test',
-          '--browser=android-content-shell', 'pixel'])
+          '--browser=android-content-shell',
+          '--generated-dir=%s' % os.path.join(data_dir, 'generated'),
+          '--reference-dir=%s' % os.path.join(data_dir, 'reference'),
+          '--build-revision=%s' % revision,
+          'pixel'])
 
   bb_annotations.PrintNamedStep('webgl_conformance_tests')
   RunCmd(['content/test/gpu/run_gpu_test',