[Telemetry] Fix a few more potential deadlocks.

This builds on https://codereview.chromium.org/385653002/ .

Many functions in Python's logging module grab a lock internally. Some
appear to do so before converting the provided message to a string via
its __str__ method.

Calling an object's __str__ method before calling a logging funciton
allows anything called by the __str__ method to log without the risk of
hitting a deadlock.

BUG=392869

Review URL: https://codereview.chromium.org/383793002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282485 0039d316-1c4b-4281-b951-d872f2087c98

tools/telemetry/telemetry/benchmark.py

@@ -127,7 +127,7 @@ class Benchmark(command_line.Command):
                       'If you believe you have credentials, follow the '
                       'instructions below.',
                       generated_profile_archive_path)
-        logging.error(e)
+        logging.error(str(e))
         sys.exit(-1)
 
     # Unzip profile directory.

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

@@ -90,7 +90,7 @@ def FindAllAvailableBrowsers(finder_options):
   except urllib2.URLError as e:
     logging.debug('Error communicating with devices over %s.'
                   % IOS_WEBKIT_DEBUG_PROXY)
-    logging.debug(e)
+    logging.debug(str(e))
     return []
 
   # TODO(baxley): Move to ios-webkit-debug-proxy command class, similar

tools/telemetry/telemetry/core/platform/linux_platform_backend.py

@@ -93,7 +93,7 @@ class LinuxPlatformBackend(
       changed |= cloud_storage.GetIfChanged(
           ipfw_mod, cloud_storage.INTERNAL_BUCKET)
     except cloud_storage.CloudStorageError, e:
-      logging.error(e)
+      logging.error(str(e))
       logging.error('You may proceed by manually installing dummynet. See: '
                     'http://info.iet.unipi.it/~luigi/dummynet/')
       sys.exit(1)
@@ -114,7 +114,7 @@ class LinuxPlatformBackend(
       cloud_storage.GetIfChanged(bin_path, cloud_storage.INTERNAL_BUCKET)
       os.chmod(bin_path, 0755)
     except cloud_storage.CloudStorageError, e:
-      logging.error(e)
+      logging.error(str(e))
       if fallback_package:
         logging.error('You may proceed by manually installing %s via:\n'
                       'sudo apt-get install %s' % (bin_name, fallback_package))