DevTools: scripts: remove manual path concatenation / splitting

Source/devtools/scripts/optimize_png_images.py

 #!/usr/bin/env python
 # Copyright (c) 2014 Google Inc. All rights reserved.
 #
 # 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.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 10 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 devtools_file_hashes
-import glob
-import hashlib
 import os
 import os.path
-import re
 import subprocess
 import sys
 
 try:
     import json
 except ImportError:
     import simplejson as json
 
 scripts_path = os.path.dirname(os.path.abspath(__file__))
 devtools_path = os.path.dirname(scripts_path)
 blink_source_path = os.path.dirname(devtools_path)
 blink_path = os.path.dirname(blink_source_path)
 chromium_src_path = os.path.dirname(os.path.dirname(blink_path))
 devtools_frontend_path = os.path.join(devtools_path, "front_end")
 images_path = os.path.join(devtools_frontend_path, "Images")
 image_sources_path = os.path.join(images_path, "src")
 hashes_file_name = "optimize_png.hashes"
 hashes_file_path = os.path.join(image_sources_path, hashes_file_name)
 
 file_names = os.listdir(image_sources_path)
 svg_file_paths = [os.path.join(image_sources_path, file_name) for file_name in file_names if file_name.endswith(".svg")]
 svg_file_paths_to_optimize = devtools_file_hashes.files_with_invalid_hashes(hashes_file_path, svg_file_paths)
-svg_file_names = [re.sub(".svg$", "", os.path.basename(file_path)) for file_path in svg_file_paths_to_optimize]
+svg_file_names = [os.path.basename(file_path) for file_path in svg_file_paths_to_optimize]
 
 optimize_script_path = os.path.join("tools", "resources", "optimize-png-files.sh")
 
 
 def check_installed(app_name, package, how_to):
     proc = subprocess.Popen("which %s" % app_name, stdout=subprocess.PIPE, shell=True)
     proc.communicate()
     if proc.returncode != 0:
         print "This script needs \"%s\" to be installed." % app_name
         if how_to:
@@ skipping 15 matching lines @@
     return proc
 
 if len(svg_file_names):
     print "%d unoptimized png files found." % len(svg_file_names)
 else:
     print "All png files are already optimized."
     sys.exit()
 
 processes = {}
 for file_name in svg_file_names:
-    name = re.sub(".svg$", "", file_name)
+    name = os.path.splitext(file_name)[0]
     name2x = name + "_2x"
     processes[name] = optimize_png(name)
     processes[name2x] = optimize_png(name2x)
 
 for file_name, proc in processes.items():
     (optimize_out, _) = proc.communicate()
     print("Optimization of %s finished: %s" % (file_name, optimize_out))
 
 devtools_file_hashes.update_file_hashes(hashes_file_path, svg_file_paths)