[tools/android/loading] Helper script running Chrome on device with WPR

tools/android/loading/chrome_setup.py

+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import subprocess
+
+
+# Command line arguments for Chrome for loading performance measurements.
+CHROME_ARGS = [
+    # Disable backgound network requests that may pollute WPR archive, pollute
+    # HTTP cache generation, and introduce noise in loading performance.
+    '--disable-background-networking',
+    '--disable-default-apps',
+    '--no-proxy-server',
+    # TODO(droger): Remove once crbug.com/354743 is fixed.
+    '--safebrowsing-disable-auto-update',
+
+    # Disables actions that chrome performs only on first run or each launches,
+    # which can interfere with page load performance, or even block its
+    # execution by waiting for user input.
+    '--disable-fre',
+    '--no-default-browser-check',
+    '--no-first-run',
+]
+
+
+def ResetChromeLocalState(device, package):
+  """Remove the Chrome Profile and the various disk caches."""
+  profile_dirs = ['app_chrome/Default', 'cache', 'app_chrome/ShaderCache',
+                  'app_tabs']
+  cmd = ['rm', '-rf']
+  cmd.extend(
+      '/data/data/{}/{}'.format(package, d) for d in profile_dirs)
+  device.adb.Shell(subprocess.list2cmdline(cmd))