[Telemtry] Set --enable-remote-debugging flag for Android.

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

Index: tools/telemetry/telemetry/core/chrome/android_browser_backend.py
diff --git a/tools/telemetry/telemetry/core/chrome/android_browser_backend.py b/tools/telemetry/telemetry/core/chrome/android_browser_backend.py
index 6bdc2232b7219d5b07e08192e58af15f36060796..6b4ffffc1332e617d42a5802ebd04c5f2569ee75 100644
--- a/tools/telemetry/telemetry/core/chrome/android_browser_backend.py
+++ b/tools/telemetry/telemetry/core/chrome/android_browser_backend.py
@@ -75,6 +75,8 @@ class AndroidBrowserBackend(browser_backend.BrowserBackend):
     args = map(QuoteIfNeeded, args)
     self._adb.Adb().SetProtectedFileContents(cmdline_file, ' '.join(args))
 
+    # TODO: Once --enable-remote-debugging flag makes its way to the oldest
+    # version under test (m27 goes to stable), remove this hack.
     # Force devtools protocol on, if not already done and we can access
     # protected files.
     if (not is_content_shell and
@@ -144,6 +146,7 @@ class AndroidBrowserBackend(browser_backend.BrowserBackend):
 
   def GetBrowserStartupArgs(self):
     args = super(AndroidBrowserBackend, self).GetBrowserStartupArgs()
+    args.append('--enable-remote-debugging')
     args.append('--disable-fre')
     return args