Improvements to unit test behavior.

- Standardize the test timeout implementation using a new TestHandler::SetTestTimeout method and enable timeouts for almost all tests. The test timeout can be disabled globally using a new `--disable-test-timeout` command-line flag.
- Wait for TestHandler object destruction at the end of each test using a new ReleaseAndWaitForDestructor function. This avoids test state leakage and verifies that no object references are leaked.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1964 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

tests/unittests/urlrequest_unittest.cc

@@ -927,6 +927,9 @@ class RequestTestHandler : public TestHandler,
     test_runner_.SetupTest(test_mode_);
 
     CreateBrowser(test_url_);
+
+    // Time out the test after a reasonable period of time.
+    SetTestTimeout();
   }
 
   CefRefPtr<CefProcessMessage> CreateTestMessage() {
@@ -1067,6 +1070,7 @@ void RegisterURLRequestCustomSchemes(
       EXPECT_TRUE(handler->got_message_); \
       EXPECT_TRUE(handler->got_success_); \
     } \
+    ReleaseAndWaitForDestructor(handler); \
   }
 
 #define REQ_TEST(name, test_mode, test_in_browser) \