webkitpy: Simplify DiffParser, removing support for SVN patches.

third_party/WebKit/Tools/Scripts/webkitpy/style/patchreader.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
 # Copyright (C) 2010 Chris Jerdonek (chris.jerdonek@gmail.com)
 # Copyright (C) 2010 ProFUSION embedded systems
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
@@ skipping 11 matching lines @@
 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import logging
-import re
 
 from webkitpy.common.checkout.diff_parser import DiffParser
-from webkitpy.common.system.filesystem import FileSystem
 
 
 _log = logging.getLogger(__name__)
 
 
 class PatchReader(object):
     """Supports checking style in patches."""
 
     def __init__(self, text_file_reader):
         """Create a PatchReader instance.
 
         Args:
           text_file_reader: A TextFileReader instance.
         """
         self._text_file_reader = text_file_reader
 
-    def check(self, patch_string, fs=None):
-        """Check style in the given patch."""
-        fs = fs or FileSystem()
+    def check(self, patch_string):
+        """Checks style in the given patch."""
         patch_files = DiffParser(patch_string.splitlines()).files
 
-        # If the user uses git, checking subversion config file only once is enough.
-        # TODO(qyearsley): Simplify this since git is now the only supported SCM system.
-        call_only_once = True
-
         for path, diff_file in patch_files.iteritems():
             line_numbers = diff_file.added_or_modified_line_numbers()
             _log.debug('Found %s new or modified lines in: %s', len(line_numbers), path)
 
             if not line_numbers:
-                match = re.search(r"\s*png$", path)
-                if match and fs.exists(path):
-                    if call_only_once:
-                        self._text_file_reader.process_file(file_path=path, line_numbers=None)
-                        call_only_once = False
-                    continue
                 # Don't check files which contain only deleted lines
                 # as they can never add style errors. However, mark them as
                 # processed so that we count up number of such files.
                 self._text_file_reader.count_delete_only_file()
                 continue
 
             self._text_file_reader.process_file(file_path=path, line_numbers=line_numbers)