Revert of Consider any testharness result with >= 1 PASS and no FAIL to be passing.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/testharness_results.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/testharness_results.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/testharness_results.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/testharness_results.py
index 8407b1d877a7ec8c49c4a3bd747139980af6e537..10994fb19b30a448300366b60ceed6426fb9f9d9 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/testharness_results.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/testharness_results.py
@@ -34,29 +34,47 @@ def is_testharness_output(content_text):
 
 
 def is_testharness_output_passing(content_text):
-    """Checks whether |content_text| is a passing testharness output.
+    """Returns whether |content_text| is a passing testharness output."""
 
-    Under a relatively loose/accepting definition of passing
-    testharness output, we consider any output with at least one
-    PASS result and no FAIL result (or TIMEOUT or NOTRUN).
-    """
-    # Leading and trailing whitespace are ignored.
+    # Leading and trailing white spaces are accepted.
     lines = content_text.strip().splitlines()
     lines = [line.strip() for line in lines]
 
-    at_least_one_pass = False
-
+    # The check is very conservative and rejects any unexpected content in the output.
+    previous_line_is_console_line = False
     for line in lines:
+        # There should be no empty lines, unless the empty line follows a console message.
+        if len(line) == 0:
+            if previous_line_is_console_line:
+                continue
+            else:
+                return False
+
+        # Those lines are expected to be exactly equivalent.
+        if line == _TESTHARNESSREPORT_HEADER or line == _TESTHARNESSREPORT_FOOTER:
+            previous_line_is_console_line = False
+            continue
+
+        # Those are expected passing output.
+        if line.startswith('CONSOLE'):
+            previous_line_is_console_line = True
+            continue
+
         if line.startswith('PASS'):
-            at_least_one_pass = True
+            previous_line_is_console_line = False
             continue
+
+        # Those are expected failing output.
         if (line.startswith('FAIL') or
                 line.startswith('TIMEOUT') or
                 line.startswith('NOTRUN') or
                 line.startswith('Harness Error. harness_status = ')):
             return False
 
-    return at_least_one_pass
+        # Unexpected output should be considered as a failure.
+        return False
+
+    return True
 
 
 def has_console_errors_or_warnings(content_text):