Various hacks for running a clang tool on Windows.

tools/clang/scripts/update.py

Index: tools/clang/scripts/update.py
diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
index 25aa5a50ee1cc646a2985927974e126b151fa706..9a07303b39fb971c798f37db335211ec593e277b 100755
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -72,6 +72,7 @@ def DeleteFiles(dir, pattern):
 
 def ClobberChromiumBuildFiles():
   """Clobber Chomium build files."""
+  return
   print 'Clobbering Chromium build files...'
   out_dir = os.path.join(CHROMIUM_DIR, 'out')
   if os.path.isdir(out_dir):
@@ -170,7 +171,7 @@ def UpdateClang():
   print 'Updating Clang to %s...' % (LLVM_WIN_REVISION)
   if LLVM_WIN_REVISION != 'HEAD' and ReadStampFile() == LLVM_WIN_REVISION:
     print 'Already up to date.'
-    return 0
+    # return 0
 
   AddCMakeToPath()
   ClobberChromiumBuildFiles()
@@ -189,9 +190,15 @@ def UpdateClang():
 
   RunCommand(GetVSVersion().SetupScript('x64') +
              ['&&', 'cmake', '-GNinja', '-DCMAKE_BUILD_TYPE=Release',
+              '-DCHROMIUM_TOOLS_SRC=%s' % os.path.join(CHROMIUM_DIR, 'tools', 'clang'),
+              '-DCHROMIUM_TOOLS=rewrite_scoped_refptr',
               '-DLLVM_ENABLE_ASSERTIONS=ON', SubversionCmakeArg(), LLVM_DIR])
   RunCommand(GetVSVersion().SetupScript('x64') + ['&&', 'ninja', 'all'])
 
+  WriteStampFile(LLVM_WIN_REVISION)
+  print 'Clang update was successful.'
+  return 0
+
   # Do an x86 build of compiler-rt to get the 32-bit ASan run-time.
   # TODO(hans): Remove once the regular build above produces this.
   if not os.path.exists(COMPILER_RT_BUILD_DIR):