[Presubmit] Make CSS checker ignore '@' inside of strings.

chrome/browser/test_presubmit.py

 #!/usr/bin/env python
 # 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.
 
 """Unit tests for Web Development Style Guide checker."""
 
 import os
 import re
 import sys
@@ skipping 437 matching lines @@
     self.input_api.re = re
     self.mox.StubOutWithMock(self.input_api, 'AffectedSourceFiles')
     self.input_api.AffectedFiles(
         include_deletes=False, file_filter=None).AndReturn([self.fake_file])
 
     # Actual creations of PresubmitPromptWarning are defined in each test.
     self.output_api = self.mox.CreateMockAnything()
     self.mox.StubOutWithMock(self.output_api, 'PresubmitPromptWarning',
                              use_mock_anything=True)
 
-    author_msg = ('Was the CSS checker useful? '
-                  'Send feedback or hate mail to dbeam@chromium.org.')
     self.output_api = self.mox.CreateMockAnything()
     self.mox.StubOutWithMock(self.output_api, 'PresubmitNotifyResult',
                              use_mock_anything=True)
-    self.output_api.PresubmitNotifyResult(author_msg).AndReturn(None)
+
+  def VerifyContentsIsValid(self, contents):
+    self.fake_file.NewContents().AndReturn(contents.splitlines())
+    self.mox.ReplayAll()
+    css_checker.CSSChecker(self.input_api, self.output_api).RunChecks()
 
   def VerifyContentsProducesOutput(self, contents, output):
     self.fake_file.NewContents().AndReturn(contents.splitlines())
+    author_msg = ('Was the CSS checker useful? '
+                  'Send feedback or hate mail to dbeam@chromium.org.')
+    self.output_api.PresubmitNotifyResult(author_msg).AndReturn(None)
     self.output_api.PresubmitPromptWarning(
         self.fake_file_name + ':\n' + output.strip()).AndReturn(None)
     self.mox.ReplayAll()
     css_checker.CSSChecker(self.input_api, self.output_api).RunChecks()
 
   def testCssAlphaWithAtBlock(self):
     self.VerifyContentsProducesOutput("""
 <include src="../shared/css/cr/ui/overlay.css">
 <include src="chrome://resources/totally-cool.css" />
 
@@ skipping 24 matching lines @@
   opacity: 1; /* TODO(dbeam): Fix this. */
 }
 </if>""", """
 - Alphabetize properties and list vendor specific (i.e. -webkit) above standard.
     display: block;
     color: red;
 
     z-index: 5;
     color: black;""")
 
+  def testCssStringWithAt(self):
+    self.VerifyContentsIsValid("""
+#logo {
+  background-image: url('images/google_logo.png@2x');
+}
+
+body.alternate-logo #logo {
+  -webkit-mask-image: url('images/google_logo.png@2x');
+  background: none;
+}
+
+.stuff1 {
+}
+
+.stuff2 {
+}
+      """)
+
   def testCssAlphaWithNonStandard(self):
     self.VerifyContentsProducesOutput("""
 div {
   /* A hopefully safely ignored comment and @media statement. /**/
   color: red;
   -webkit-margin-start: 5px;
 }""", """
 - Alphabetize properties and list vendor specific (i.e. -webkit) above standard.
     color: red;
     -webkit-margin-start: 5px;""")
@@ skipping 249 matching lines @@
     opacity: .0;
     opacity: 0.0;
     opacity: 0.;
     border-width: 0mm;
     height: 0cm;
     width: 0in;
 """)
 
 if __name__ == '__main__':
   unittest.main()