Adding Java style presubmit check.

PRESUBMIT.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Top-level presubmit script for Chromium.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into gcl.
 """
 
@@ skipping 958 matching lines @@
         cygwin_shell.append(f.LocalPath())
         break
 
   if cygwin_shell:
     return [output_api.PresubmitError(
       'These files should not use msvs_cygwin_shell (the default is 0):',
       items=cygwin_shell)]
   return []
 
 
+def _CheckJavaStyle(input_api, output_api):
+  """Runs checkstyle on changed java files and returns errors if any exist."""
+  original_sys_path = sys.path
+  try:
+    sys.path = sys.path + [input_api.os_path.join(
+        input_api.PresubmitLocalPath(), 'tools', 'android', 'checkstyle')]
+    import checkstyle
+  finally:
+    # Restore sys.path to what it was before.
+    sys.path = original_sys_path
+
+  return checkstyle.RunCheckstyle(
+      input_api, output_api, 'tools/android/checkstyle/chromium-style-5.0.xml')
+
+
 def _CommonChecks(input_api, output_api):
   """Checks common to both upload and commit."""
   results = []
   results.extend(input_api.canned_checks.PanProjectChecks(
       input_api, output_api, excluded_paths=_EXCLUDED_PATHS))
   results.extend(_CheckAuthorizedAuthor(input_api, output_api))
   results.extend(
-    _CheckNoProductionCodeUsingTestOnlyFunctions(input_api, output_api))
+      _CheckNoProductionCodeUsingTestOnlyFunctions(input_api, output_api))
   results.extend(_CheckNoIOStreamInHeaders(input_api, output_api))
   results.extend(_CheckNoUNIT_TESTInSourceFiles(input_api, output_api))
   results.extend(_CheckNoNewWStrings(input_api, output_api))
   results.extend(_CheckNoDEPSGIT(input_api, output_api))
   results.extend(_CheckNoBannedFunctions(input_api, output_api))
   results.extend(_CheckNoPragmaOnce(input_api, output_api))
   results.extend(_CheckNoTrinaryTrueFalse(input_api, output_api))
   results.extend(_CheckUnwantedDependencies(input_api, output_api))
   results.extend(_CheckFilePermissions(input_api, output_api))
   results.extend(_CheckNoAuraWindowPropertyHInHeaders(input_api, output_api))
   results.extend(_CheckIncludeOrder(input_api, output_api))
   results.extend(_CheckForVersionControlConflicts(input_api, output_api))
   results.extend(_CheckPatchFiles(input_api, output_api))
   results.extend(_CheckHardcodedGoogleHostsInLowerLayers(input_api, output_api))
   results.extend(_CheckNoAbbreviationInPngFileName(input_api, output_api))
   results.extend(_CheckForInvalidOSMacros(input_api, output_api))
   results.extend(_CheckAddedDepsHaveTargetApprovals(input_api, output_api))
   results.extend(
       input_api.canned_checks.CheckChangeHasNoTabs(
           input_api,
           output_api,
           source_file_filter=lambda x: x.LocalPath().endswith('.grd')))
   results.extend(_CheckSpamLogging(input_api, output_api))
   results.extend(_CheckForAnonymousVariables(input_api, output_api))
   results.extend(_CheckCygwinShell(input_api, output_api))
+  results.extend(_CheckJavaStyle(input_api, output_api))
 
   if any('PRESUBMIT.py' == f.LocalPath() for f in input_api.AffectedFiles()):
     results.extend(input_api.canned_checks.RunUnitTestsInDirectory(
         input_api, output_api,
         input_api.PresubmitLocalPath(),
         whitelist=[r'^PRESUBMIT_test\.py$']))
   return results
 
 
 def _CheckSubversionConfig(input_api, output_api):
@@ skipping 207 matching lines @@
     trybots += ['cros_x86']
 
   # The AOSP bot doesn't build the chrome/ layer, so ignore any changes to it
   # unless they're .gyp(i) files as changes to those files can break the gyp
   # step on that bot.
   if (not all(re.search('^chrome', f) for f in files) or
       any(re.search('\.gypi?$', f) for f in files)):
     trybots += ['android_aosp']
 
   return trybots