[Telemetry] Allows concatenating multiple Disabled & Enabled decorators

tools/telemetry/telemetry/decorators.py

Index: tools/telemetry/telemetry/decorators.py
diff --git a/tools/telemetry/telemetry/decorators.py b/tools/telemetry/telemetry/decorators.py
index 8865408108e21391ee9da919532dd84601b5f989..abcfa9f952eb3d42fb6f6d550f98c57ecd56ee35 100644
--- a/tools/telemetry/telemetry/decorators.py
+++ b/tools/telemetry/telemetry/decorators.py
@@ -99,8 +99,6 @@ class Deprecated(object):
 def Disabled(*args):
   """Decorator for disabling tests/benchmarks.
 
-  May be used without args to unconditionally disable:
-    @Disabled  # Unconditionally disabled.
 
   If args are given, the test will be disabled if ANY of the args match the
   browser type, OS name or OS version:
@@ -108,19 +106,17 @@ def Disabled(*args):
     @Disabled('win')           # Disabled on Windows.
     @Disabled('win', 'linux')  # Disabled on both Windows and Linux.
     @Disabled('mavericks')     # Disabled on Mac Mavericks (10.9) only.
+    @Disabled('all')  # Unconditionally disabled.
   """
   def _Disabled(func):
-    if not isinstance(func, types.FunctionType):
-      func._disabled_strings = disabled_strings
-      return func
-    @functools.wraps(func)
-    def wrapper(*args, **kwargs):
-      func(*args, **kwargs)
-    wrapper._disabled_strings = disabled_strings
-    return wrapper
-  if len(args) == 1 and callable(args[0]):
-    disabled_strings = []
-    return _Disabled(args[0])
+    if not hasattr(func, '_disabled_strings'):
+      func._disabled_strings = set()
+    func._disabled_strings.update(disabled_strings)
+    return func
+  assert args, (
+      "@Disabled(...) requires arguments. Use @Disabled('all') if you want to "
+      'unconditionally disable the test.')
+  assert not callable(args[0]), 'Please use @Disabled(..).'
   disabled_strings = list(args)
   for disabled_string in disabled_strings:
     # TODO(tonyg): Validate that these strings are recognized.
@@ -139,15 +135,12 @@ def Enabled(*args):
     @Enabled('mavericks')     # Enabled only on Mac Mavericks (10.9).
   """
   def _Enabled(func):
-    if not isinstance(func, types.FunctionType):
-      func._enabled_strings = enabled_strings
-      return func
-    @functools.wraps(func)
-    def wrapper(*args, **kwargs):
-      func(*args, **kwargs)
-    wrapper._enabled_strings = enabled_strings
-    return wrapper
-  assert args and not callable(args[0]), '@Enabled requires arguments'
+    if not hasattr(func, '_enabled_strings'):
+      func._enabled_strings = set()
+    func._enabled_strings.update(enabled_strings)
+    return func
+  assert args, '@Enabled(..) requires arguments'
+  assert not callable(args[0]), 'Please use @Enabled(..).'
   enabled_strings = list(args)
   for enabled_string in enabled_strings:
     # TODO(tonyg): Validate that these strings are recognized.
@@ -180,6 +173,7 @@ def Isolated(*args):
   return _Isolated
 
 
+# TODO(nednguyen): Remove this and have call site just use ShouldSkip directly.
 def IsEnabled(test, possible_browser):
   """Returns True iff |test| is enabled given the |possible_browser|.
 
@@ -220,14 +214,14 @@ def ShouldSkip(test, possible_browser):
   running = 'You are running %r.' % platform_attributes
 
   if hasattr(test, '_disabled_strings'):
-    if not test._disabled_strings:
+    if 'all' in test._disabled_strings:
       return (True, '%s it is unconditionally disabled.' % skip)
     if set(test._disabled_strings) & set(platform_attributes):
       return (True, '%s it is disabled for %s. %s' %
                       (skip, ' and '.join(test._disabled_strings), running))
 
   if hasattr(test, '_enabled_strings'):
-    if not test._enabled_strings:
+    if 'all' in test._enabled_strings:
       return False, None  # No arguments to @Enabled means always enable.
     if not set(test._enabled_strings) & set(platform_attributes):
       return (True, '%s it is only enabled for %s. %s' %