tools/android/loading: Lets some execption pass through chrome controller's Open

tools/android/loading/controller.py

Index: tools/android/loading/controller.py
diff --git a/tools/android/loading/controller.py b/tools/android/loading/controller.py
index 279d0ba81a71783fecea00539c2401b911db9144..aede30224cd255f3e5d099323cbd4e95bc2aae97 100644
--- a/tools/android/loading/controller.py
+++ b/tools/android/loading/controller.py
@@ -82,6 +82,7 @@ class ChromeControllerError(Exception):
   """
   _INTERMITTENT_WHITE_LIST = {websocket.WebSocketTimeoutException,
                               devtools_monitor.DevToolsConnectionTargetCrashed}
+  _PASSTHROUGH_WHITE_LIST = (MemoryError, SyntaxError)

[pasko, 2016/06/01 12:47:17]

wow, interesting, did you actually hit a memory error?
are there other unrecoverable errors we want to stop on?

[gabadie, 2016/06/01 12:54:43]

It is not obvious in this CL but there is exceptions such as SystemExit or
KeyboardInterupt are not in subclasses of Exception but ExceptionBase. But the
except: implictly does a except ExceptionBase, the reason why we change below
from except: to except Exception:.

The issue is that there is some exception such as the one listed here that are
still subclasses of Exception, the reason we are doing this
_PASSTHROUGH_WHITE_LIST.

[pasko, 2016/06/01 13:42:22]

thanks, it is indeed not obvious

 
   def __init__(self, log):
     """Constructor
@@ -354,7 +355,9 @@ class RemoteChromeController(ChromeControllerBase):
           raise ChromeControllerInternalError(
               'Failed to connect to Chrome devtools after {} '
               'attempts.'.format(self.DEVTOOLS_CONNECTION_ATTEMPTS))
-      except:
+      except ChromeControllerError._PASSTHROUGH_WHITE_LIST:
+        raise
+      except Exception:
         logcat = ''.join([l + '\n' for l in self._device.adb.Logcat(dump=True)])
         raise ChromeControllerError(log=logcat)
       finally:
@@ -520,7 +523,9 @@ class LocalChromeController(ChromeControllerBase):
         connection.Close()
         chrome_process.wait()
         chrome_process = None
-    except:
+    except ChromeControllerError._PASSTHROUGH_WHITE_LIST:
+      raise
+    except Exception:
       raise ChromeControllerError(log=open(tmp_log.name).read())
     finally:
       if OPTIONS.local_noisy: