Bug 1223277 - Improve Marionette unit tests for delayed crashes. r=ato

In case of delayed shutdowns of Firefox we currently miss to detect the
created minidump files because the mozcrash mock gets removed right after
the crash causing command has been executed. To prevent this the mock
has to be active from setUp until tearDown.

Also we should not silently ignore the case that the minidump folder
cannot be deleted. Because it means no crash happened, or the folder
has not been created.

MozReview-Commit-ID: KncJ5BHi7M5

--HG--
extra : rebase_source : 63c947b0a7fe16de0eed19a8e0359721d9f4051d

testing/marionette/harness/marionette_harness/tests/unit/test_crash.py

@@ -31,7 +31,7 @@ class MockMozCrash(object):
 
     def check_for_crashes(self, dump_directory, *args, **kwargs):
         minidump_files = glob.glob('{}/*.dmp'.format(dump_directory))
-        shutil.rmtree(dump_directory, ignore_errors=True)
+        shutil.rmtree(dump_directory)
 
         if self.crash_reporter_enabled:
             return len(minidump_files)
@@ -50,12 +50,18 @@ class BaseCrashTestCase(MarionetteTestCase):
     def setUp(self):
         super(BaseCrashTestCase, self).setUp()
 
-        self.mozcrash_mock = MockMozCrash(self.marionette)
+        # Monkey patch mozcrash to avoid crash info output only for our triggered crashes.
+        self.mozcrash = runner.mozcrash
+        runner.mozcrash = MockMozCrash(self.marionette)
+
         self.crash_count = self.marionette.crashed
         self.pid = self.marionette.process_id
         self.remote_uri = self.marionette.absolute_url("javascriptPage.html")
 
     def tearDown(self):
+        # Replace mockup with original mozcrash instance
+        runner.mozcrash = self.mozcrash
+
         self.marionette.crashed = self.crash_count
 
         super(BaseCrashTestCase, self).tearDown()
@@ -64,15 +70,11 @@ class BaseCrashTestCase(MarionetteTestCase):
         context = 'chrome' if chrome else 'content'
         sandbox = None if chrome else 'system'
 
-        # Monkey patch mozcrash to avoid crash info output only for our triggered crashes.
-        mozcrash = runner.mozcrash
-        runner.mozcrash = self.mozcrash_mock
-
         socket_timeout = self.marionette.client.socket_timeout
+        self.marionette.client.socket_timeout = self.socket_timeout
 
         self.marionette.set_context(context)
         try:
-            self.marionette.client.socket_timeout = self.socket_timeout
             self.marionette.execute_script("""
               // Copied from crash me simple
               Components.utils.import("resource://gre/modules/ctypes.jsm");
@@ -83,7 +85,6 @@ class BaseCrashTestCase(MarionetteTestCase):
               var crash = badptr.contents;
             """, sandbox=sandbox)
         finally:
-            runner.mozcrash = mozcrash
             self.marionette.client.socket_timeout = socket_timeout
 
 
@@ -100,13 +101,10 @@ class TestCrash(BaseCrashTestCase):
         self.marionette.start_session()
         self.assertNotEqual(self.marionette.process_id, self.pid)
 
-        # TODO: Bug 1314594 - Causes a hang for the communication between the
-        # chrome and frame script.
-        # self.marionette.get_url()
+        self.marionette.get_url()
 
     @run_if_e10s("Content crashes only exist in e10s mode")
     def test_crash_content_process(self):
-        # If e10s is disabled the chrome process crashes
         self.marionette.navigate(self.remote_uri)
 
         self.assertRaisesRegexp(IOError, 'Content process crashed',