[Telemetry] Print out the flash path for the chosen brower.

This is to help diagnose an issue where the perf bots seem to be running without
flash.

BUG=416849

Review URL: https://codereview.chromium.org/597213002

Cr-Commit-Position: refs/heads/master@{#296445}

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

@@ -33,8 +33,8 @@ class PossibleDesktopBrowser(possible_browser.PossibleBrowser):
     self.is_local_build = is_local_build
 
   def __repr__(self):
-    return 'PossibleDesktopBrowser(browser_type=%s, executable=%s)' % (
-        self.browser_type, self._local_executable)
+    return 'PossibleDesktopBrowser(type=%s, executable=%s, flash=%s)' % (
+        self.browser_type, self._local_executable, self._flash_path)
 
   def _InitPlatformIfNeeded(self):
     if self._platform: