android: Add browser type for webview shell to telemetry

This adds a browser type 'android-webview-shell' for the test
shell activity (AndroidWebView.apk), which is different from the existing
'android-webview' target that uses the device's system WebView for
testing.

Review URL: https://codereview.chromium.org/517573004

Cr-Commit-Position: refs/heads/master@{#292734}

tools/telemetry/telemetry/core/backends/chrome/android_browser_backend.py

@@ -133,12 +133,12 @@ class ChromeShellBackendSettings(AndroidBrowserBackendSettings):
   def GetDevtoolsRemotePort(self):
     return 'localabstract:chrome_shell_devtools_remote'
 
-
 class WebviewBackendSettings(AndroidBrowserBackendSettings):
-  def __init__(self, adb, package):
+  def __init__(self, adb, package,
+               activity='org.chromium.telemetry_shell.TelemetryActivity'):
     super(WebviewBackendSettings, self).__init__(
         adb=adb,
-        activity='org.chromium.telemetry_shell.TelemetryActivity',
+        activity=activity,
         cmdline_file='/data/local/tmp/webview-command-line',
         package=package,
         pseudo_exec_name='webview',
@@ -166,6 +166,12 @@ class WebviewBackendSettings(AndroidBrowserBackendSettings):
                                               'Timeout waiting for PID.')
     return 'localabstract:webview_devtools_remote_%s' % str(pid)
 
+class WebviewShellBackendSettings(WebviewBackendSettings):
+  def __init__(self, adb, package):
+    super(WebviewShellBackendSettings, self).__init__(
+        adb=adb,
+        activity='org.chromium.android_webview.shell.AwShellActivity',
+        package=package)
 
 class AndroidBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
   """The backend for controlling a browser instance running on Android."""

tools/telemetry/telemetry/core/backends/chrome/android_browser_finder.py

@@ -39,6 +39,10 @@ CHROME_PACKAGE_NAMES = {
       ['org.chromium.telemetry_shell',
        android_browser_backend.WebviewBackendSettings,
        None],
+  'android-webview-shell':
+      ['org.chromium.android_webview.shell',
+       android_browser_backend.WebviewShellBackendSettings,
+       'AndroidWebView.apk'],
   'android-chrome':
       ['com.google.android.apps.chrome',
        android_browser_backend.ChromeBackendSettings,