Add gfx_unittests to Android test (dbg, rel) bots.

scripts/slave/recipes/chromium.expected/full_chromium_linux_Android_Tests__dbg_.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "chromium.linux",
       "--builder",
       "Android Tests (dbg)",
@@ skipping 586 matching lines @@
     },
     "name": "events_unittests"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/test_runner.py",
       "gtest",
       "-s",
+      "gfx_unittests",
+      "--verbose",
+      "--flakiness-dashboard-server=http://test-results.appspot.com",
+      "--json-results-file",
+      "/path/to/tmp/json"
+    ],
+    "env": {
+      "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
+    },
+    "name": "gfx_unittests"
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "[SLAVE_BUILD]/src/build/android/test_runner.py",
+      "gtest",
+      "-s",
       "gl_tests",
       "--verbose",
       "--flakiness-dashboard-server=http://test-results.appspot.com",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "gl_tests"
@@ skipping 324 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@import glob, os, sys@@@",
       "@@@STEP_LOG_LINE@python.inline@for report in glob.glob(sys.argv[1]):@@@",
       "@@@STEP_LOG_LINE@python.inline@  with open(report, 'r') as f:@@@",
       "@@@STEP_LOG_LINE@python.inline@    for l in f.readlines():@@@",
       "@@@STEP_LOG_LINE@python.inline@      print l@@@",
       "@@@STEP_LOG_LINE@python.inline@  os.remove(report)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   }
 ]