Implement should().message() for in-task message display

third_party/WebKit/LayoutTests/webaudio/unit-tests/audit-failures-expected.txt

 CONSOLE ERROR: line 39: [audit.js] this test requires the explicit comparison with the expected result when it runs with run-webkit-tests.
 This is a testharness.js-based test.
 PASS # AUDIT TASK RUNNER STARTED. 
 PASS > [basic-failure] Testing basic assertion failures. 
 FAIL X Setting foo to bar incorrectly threw ReferenceError: "bar is not defined". assert_true: expected true got false
 FAIL X function () { var foo = 0; } did not throw an exception. assert_true: expected true got false
 FAIL X 3 < 5 is not true. Got false. assert_true: expected true got false
 FAIL X true is not false. Got true. assert_true: expected true got false
 FAIL X The number of channels is not equal to 2. Got 1. assert_true: expected true got false
 FAIL X 1 should not be equal to 1. Got 1. assert_true: expected true got false
 FAIL X typeof 3.141592 is not equal to string. Got number. assert_true: expected true got false
 FAIL X 1 is not greater than 2. Got 1. assert_true: expected true got false
 FAIL X 1 is not greater than or equal to 2. Got 1. assert_true: expected true got false
 FAIL X 2 is not less than 1. Got 2. assert_true: expected true got false
 FAIL X 2 is not less than or equal to 1. Got 2. assert_true: expected true got false
 FAIL X 1 is not equal to 2. Got 1. assert_true: expected true got false
 FAIL X should(1).beEqualTo(2) is not true. Got false. assert_true: expected true got false
+FAIL X The message is false! Got false. assert_true: expected true got false
 FAIL X Decoding audio data with no argument rejected incorrectly with TypeError: Failed to execute 'decodeAudioData' on 'BaseAudioContext': 1 argument required, but only 0 present.. Got undefined. assert_true: expected true got false
 FAIL X Suspending OAC with no argument rejected correctly but got TypeError instead of IndexSizeError. Got undefined. assert_true: expected true got false
 FAIL X Start OAC rendering resolved incorrectly. Got undefined. assert_true: expected true got false
-FAIL < [basic-failure] 16 out of 16 assertions were failed. assert_true: expected true got false
+FAIL < [basic-failure] 17 out of 17 assertions were failed. assert_true: expected true got false
 PASS > [numerical-failures] Testing numerical assertion failures. 
 FAIL X 0 is not close to 0.1 within a relative error of 0 (RelErr=1). Got 0. assert_true: expected true got false
 FAIL X The measured decibel is not close to 62 within a relative error of 0.01 (RelErr=0.04838709677419355). Got 59. assert_true: expected true got false
 FAIL X Expected 5 for all values but found 7 unexpected values: 
         Index   Actual
         [0]     1
         [1]     8
         [2]     11
         [3]     18
         ...and 3 more errors. assert_true: expected true got false
@@ skipping 31 matching lines @@
         [1]     2.0000000000000001e-1   5.9999999999999998e-1   3.9999999999999997e-1   6.6666666666666663e-1   5.9999999999999998e-2
         [2]     2.9999999999999999e-1   5.0000000000000000e-1   2.0000000000000001e-1   4.0000000000000002e-1   5.0000000000000003e-2
         [4]     5.0000000000000000e-1   2.9999999999999999e-1   2.0000000000000001e-1   6.6666666666666674e-1   2.9999999999999999e-2
         [5]     5.9999999999999998e-1   2.0000000000000001e-1   3.9999999999999997e-1   1.9999999999999998e+0   2.0000000000000004e-2
         Max AbsError of 5.9999999999999998e-1 at index of 0.
         Max RelError of 5.9999999999999991e+0 at index of 6. assert_true: expected true got false
 FAIL < [numerical-failures] 10 out of 10 assertions were failed. assert_true: expected true got false
 FAIL # AUDIT TASK RUNNER FINISHED: 2 out of 2 tasks were failed. assert_true: expected true got false
 Harness: the test ran to completion.