Reland "[Perf] Update Pixel2 FYI perf bot to MonoChrome6432.aab."

This is a reland of e3d9c6d3

Original change's description:
> [Perf] Update Pixel2 FYI perf bot to MonoChrome6432.aab.
>
> This will update the Pixel2 bots to use the MonoChrome6432.aab which is a 64bit
> browser. In making this change a new 'exact_browser' option is added to
> tester_config in perf_data_generator to allow specifying a particular binary to
> be run rather than guessing.
>
> Reland of: https://chromium-review.googlesource.com/c/chromium/src/+/1511455
>
> TBR=crouleau@chromium.org,perezju@chromium.org
> BUG=934251
>
> Change-Id: I21bf7ae8e42f0e4c127748eeecc58a8af34334a1
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1587563
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Auto-Submit: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#654862}

TBR=crouleau@chromium.org
TBR=perezju@chromium.org

Bug: 934251
Change-Id: I18a8dcb554f52ddff6e1b39d02566faff67c68a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1599614
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657640}

testing/buildbot/chromium.perf.fyi.json

@@ -52,8 +52,10 @@
       {
         "args": [
           "-v",
-          "--browser=android-chrome",
+          "--browser=exact",
           "--upload-results",
+          "--browser-executable=../../out/Release/bin/monochrome_64_32_bundle",
+          "--device=android",
           "--run-ref-build",
           "--test-shard-map-filename=android-pixel2-perf_map.json"
         ],

tools/perf/core/perf_data_generator.py

@@ -138,6 +138,7 @@ FYI_BUILDERS = {
       }
     ],
     'platform': 'android-chrome',
+      'browser': 'bin/monochrome_64_32_bundle',
     'dimension': {
       'pool': 'chrome.tests.perf-fyi',
       'os': 'Android',
@@ -1037,6 +1038,8 @@ def generate_telemetry_args(tester_config):
   # For trybot testing we always use the reference build
   if tester_config.get('testing', False):
     browser_name = 'reference'
+  elif 'browser' in tester_config:
+    browser_name = 'exact'
   elif tester_config['platform'] == 'android':
     browser_name = 'android-chromium'
   elif tester_config['platform'].startswith('android-'):
@@ -1053,7 +1056,13 @@ def generate_telemetry_args(tester_config):
     '--upload-results'
   ]
 
-  if browser_name.startswith('android-webview'):
+  if 'browser' in tester_config:
+    test_args.append('--browser-executable=../../out/Release/%s' %
+                     tester_config['browser'])
+    if tester_config['platform'].startswith('android'):
+      test_args.append('--device=android')
+
+  if tester_config['platform'].startswith('android-webview'):
     test_args.append(
         '--webview-embedder-apk=../../out/Release/apks/SystemWebViewShell.apk')
 

tools/perf/core/perf_data_generator_unittest.py

@@ -97,6 +97,61 @@ class PerfDataGeneratorTest(unittest.TestCase):
       }
     self.assertEquals(returned_test, expected_generated_test)
 
+  def testGeneratePerformanceTestSuiteExact(self):
+    swarming_dimensions = [
+        {'os': 'SkyNet', 'pool': 'T-RIP'}
+    ]
+    test_config = {
+        'platform': 'android-webview',
+        'browser': 'bin/monochrome_64_32_bundle',
+        'dimension': swarming_dimensions,
+    }
+    test = {
+        'isolate': 'performance_test_suite',
+        'extra_args': [
+            '--run-ref-build',
+            '--test-shard-map-filename=shard_map.json',
+          ],
+        'num_shards': 26
+    }
+    returned_test = perf_data_generator.generate_performance_test(
+        test_config, test)
+
+    expected_generated_test = {
+        'override_compile_targets': ['performance_test_suite'],
+        'isolate_name': 'performance_test_suite',
+        'args': ['-v', '--browser=exact', '--upload-results',
+                 '--browser-executable=../../out/Release'
+                 '/bin/monochrome_64_32_bundle',
+                 '--device=android',
+                 '--webview-embedder-apk=../../out/Release'
+                 '/apks/SystemWebViewShell.apk',
+                 '--run-ref-build',
+                 '--test-shard-map-filename=shard_map.json'],
+        'trigger_script': {
+          'args': [
+            '--multiple-dimension-script-verbose',
+            'True'
+          ],
+          'requires_simultaneous_shard_dispatch': True,
+          'script': '//testing/trigger_scripts/perf_device_trigger.py'
+        },
+        'merge': {
+          'script': '//tools/perf/process_perf_results.py'
+        },
+        'swarming': {
+          'ignore_task_failure': False,
+          'can_use_on_swarming_builders': True,
+          'expiration': 7200,
+          'io_timeout': 1800,
+          'hard_timeout': 36000,
+          'dimension_sets': [[{'os': 'SkyNet', 'pool': 'T-RIP'}]],
+          'shards': 26
+        },
+        'name': 'performance_test_suite'
+      }
+    self.assertEquals(returned_test, expected_generated_test)
+
   def testGeneratePerformanceTestSuiteWebview(self):
     swarming_dimensions = [
         {'os': 'SkyNet', 'pool': 'T-RIP'}

tools/perf/core/perf_json_config_validator.py

@@ -86,17 +86,18 @@ def _ValidateBrowserType(builder_name, test_config):
   browser_options = _ParseBrowserFlags(test_config['args'])
   if 'WebView' in builder_name or 'webview' in builder_name:
     if browser_options.browser not in (
-        'android-webview', 'android-webview-google'):
+        'android-webview', 'android-webview-google', 'exact'):
       raise ValueError(
-          "%s must use 'android-webview' or 'android-webview-google' browser" %
-          builder_name)
+          "%s must use 'android-webview', 'android-webview-google' or 'exact' "
+          "browser" % builder_name)
     if not browser_options.webview_embedder_apk:
       raise ValueError('%s must set --webview-embedder-apk flag' % builder_name)
   elif 'Android' in builder_name or 'android' in builder_name:
-    if browser_options.browser not in ('android-chromium', 'android-chrome'):
+    if browser_options.browser not in (
+        'android-chromium', 'android-chrome', 'exact'):
       raise ValueError(
-          "%s must use 'android-chromium' or 'android-chrome' browser" %
-          builder_name)
+          "%s must use 'android-chromium', 'android-chrome' or 'exact' "
+          "browser" % builder_name)
   elif builder_name in ('win-10-perf', 'Win 7 Nvidia GPU Perf'):
     if browser_options.browser != 'release_x64':
       raise ValueError("%s must use 'release_x64' browser type" %