Workaround shutil.rmtree limitation on Windows

By default, shutil.rmtree raises an exception when deleting readonly
files on Windows.

Replace all shutil.rmtree with platform_utils.rmtree, which adds an
error handler to make files read-write when they can't be deleted.

Change-Id: I9cfea9a7b3703fb16a82cf69331540c2c179ed53

subcmds/gitc_delete.py

@@ -14,10 +14,10 @@
 # limitations under the License.
 
 from __future__ import print_function
-import shutil
 import sys
 
 from command import Command, GitcClientCommand
+import platform_utils
 
 from pyversion import is_python3
 if not is_python3():
@@ -50,4 +50,4 @@ and all locally downloaded sources.
       if not response == 'yes':
         print('Response was not "yes"\n Exiting...')
         sys.exit(1)
-    shutil.rmtree(self.gitc_manifest.gitc_client_dir)
+    platform_utils.rmtree(self.gitc_manifest.gitc_client_dir)

subcmds/init.py

@@ -17,7 +17,6 @@ from __future__ import print_function
 import os
 import platform
 import re
-import shutil
 import sys
 
 from pyversion import is_python3
@@ -35,6 +34,7 @@ from error import ManifestParseError
 from project import SyncBuffer
 from git_config import GitConfig
 from git_command import git_require, MIN_GIT_VERSION
+import platform_utils
 
 class Init(InteractiveCommand, MirrorSafeCommand):
   common = True
@@ -252,7 +252,7 @@ to update the working directory files.
       # Better delete the manifest git dir if we created it; otherwise next
       # time (when user fixes problems) we won't go through the "is_new" logic.
       if is_new:
-        shutil.rmtree(m.gitdir)
+        platform_utils.rmtree(m.gitdir)
       sys.exit(1)
 
     if opt.manifest_branch:

subcmds/sync.py

@@ -19,7 +19,6 @@ import netrc
 from optparse import SUPPRESS_HELP
 import os
 import re
-import shutil
 import socket
 import subprocess
 import sys
@@ -73,6 +72,7 @@ from project import Project
 from project import RemoteSpec
 from command import Command, MirrorSafeCommand
 from error import RepoChangedException, GitError, ManifestParseError
+import platform_utils
 from project import SyncBuffer
 from progress import Progress
 from wrapper import Wrapper
@@ -473,7 +473,7 @@ later is required to fix a server side protocol bug.
     # working git repository around. There shouldn't be any git projects here,
     # so rmtree works.
     try:
-      shutil.rmtree(os.path.join(path, '.git'))
+      platform_utils.rmtree(os.path.join(path, '.git'))
     except OSError:
       print('Failed to remove %s' % os.path.join(path, '.git'), file=sys.stderr)
       print('error: Failed to delete obsolete path %s' % path, file=sys.stderr)