ui:app_list Presubmit fix

The presubmit wasn't working on app_list because the regular expression was looking for files in a cc/ dir.

Also swept app_list folder for any presubmit errors

Review URL: https://codereview.chromium.org/730743002

Cr-Commit-Position: refs/heads/master@{#306038}
diff --git a/ui/app_list/PRESUBMIT.py b/ui/app_list/PRESUBMIT.py
index ec96af4..591fad12 100644
--- a/ui/app_list/PRESUBMIT.py
+++ b/ui/app_list/PRESUBMIT.py
@@ -7,25 +7,16 @@
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.
 """
-
-CC_SOURCE_FILES=(r'^cc/.*\.(cc|h)$',)
+INCLUDE_CPP_FILES_ONLY = (
+  r'.*\.cc$', r'.*\.h$'
+)
 
 def CheckChangeLintsClean(input_api, output_api):
-  input_api.cpplint._cpplint_state.ResetErrorCounts()  # reset global state
-  source_filter = lambda x: input_api.FilterSourceFile(
-    x, white_list=CC_SOURCE_FILES, black_list=None)
-  files = [f.AbsoluteLocalPath() for f in
-           input_api.AffectedSourceFiles(source_filter)]
-  level = 1  # strict, but just warn
-
-  for file_name in files:
-    input_api.cpplint.ProcessFile(file_name, level)
-
-  if not input_api.cpplint._cpplint_state.error_count:
-    return []
-
-  return [output_api.PresubmitPromptWarning(
-    'Changelist failed cpplint.py check.')]
+  """Makes sure that the ui/app_list/ code is cpplint clean."""
+  sources = lambda x: input_api.FilterSourceFile(
+    x, white_list = INCLUDE_CPP_FILES_ONLY, black_list = None)
+  return input_api.canned_checks.CheckChangeLintsClean(
+      input_api, output_api, sources)
 
 def CheckChangeOnUpload(input_api, output_api):
   results = []