Enable pre-test flashing for base_unittests on internal CrOS HW testers.

This tests it out on a single test suite. If it looks good, it'll be
rolled out more broadly.

This will let us tear-down all the out-of-band flashing logic for
these devices, and replace it with on-demand pre-test flashing. The
latter being much simpler to maintain, having less moving parts, and
generally being more visible.

Bug: 1057152
Change-Id: Ic2fba3725b01bec2d3dedc4898e8acfe3ad5b22d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2261702Reviewed-by: Erik Chen <erikchen@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781967}

build/chromeos/test_runner.py

@@ -120,6 +120,8 @@ class RemoteTest(object):
           '--results-dest-dir',
           os.path.join(args.logs_dir, 'system_logs')
       ]
+    if args.flash:
+      self._test_cmd += ['--flash']
 
     # This environment variable is set for tests that have been instrumented
     # for code coverage. Its incoming value is expected to be a location
@@ -806,6 +808,11 @@ def add_common_args(*parsers):
         dest='logs_dir',
         help='Will copy everything under /var/log/ from the device after the '
         'test into the specified dir.')
+    parser.add_argument(
+        '--flash',
+        action='store_true',
+        help='Will flash the device to the current SDK version before running '
+        'the test.')
 
     vm_or_device_group = parser.add_mutually_exclusive_group()
     vm_or_device_group.add_argument(

testing/buildbot/chrome.ci.json

@@ -1457,7 +1457,8 @@
     "gtest_tests": [
       {
         "args": [
-          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter"
+          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter",
+          "--flash"
         ],
         "merge": {
           "args": [],
@@ -1621,7 +1622,8 @@
     "gtest_tests": [
       {
         "args": [
-          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter"
+          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter",
+          "--flash"
         ],
         "merge": {
           "args": [],

testing/buildbot/chrome.json

@@ -827,7 +827,8 @@
     "gtest_tests": [
       {
         "args": [
-          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter"
+          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter",
+          "--flash"
         ],
         "merge": {
           "args": [],
@@ -991,7 +992,8 @@
     "gtest_tests": [
       {
         "args": [
-          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter"
+          "--test-launcher-filter-file=../../testing/buildbot/filters/chromeos.base_unittests.filter",
+          "--flash"
         ],
         "merge": {
           "args": [],

testing/buildbot/test_suite_exceptions.pyl

@@ -90,6 +90,21 @@
       'Linux FYI GPU TSAN Release',
     ],
   },
+  'base_unittests': {
+    'modifications': {
+      # TODO(crbug.com/1057152): Turn on flashing for all CrOS device tests.
+      'chromeos-eve-chrome': {
+        'args': [
+          '--flash',
+        ],
+      },
+      'chromeos-kevin-chrome': {
+        'args': [
+          '--flash',
+        ],
+      },
+    },
+  },
   'blink_web_tests': {
     'remove_from': [
       'Win 7 Tests x64 (1)',  # 64-bit win is unsupported by the layout tests.