win: Unconditionally download clang during runhooks

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 dc7a439b2980359e2a8f26a5d65dd5b5448b0f8a..5fa6812213087f7e89907af1f576bf7af745880d 100755
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -862,20 +862,7 @@ def main():
     args.lto_gold_plugin = False
 
   if args.if_needed:
-    is_clang_required = False
-    # clang is always used on Mac and Linux.
-    if sys.platform == 'darwin' or sys.platform.startswith('linux'):
-      is_clang_required = True
-    # clang requested via $GYP_DEFINES.
-    if re.search(r'\b(clang|asan|lsan|msan|tsan)=1',
-                 os.environ.get('GYP_DEFINES', '')):
-      is_clang_required = True
-    # clang previously downloaded, keep it up to date.
-    # If you don't want this, delete third_party/llvm-build on your machine.
-    if os.path.isdir(LLVM_BUILD_DIR):
-      is_clang_required = True
-    if not is_clang_required:
-      return 0

[hans, 2017/02/21 17:47:06]

Nice!

+    # TODO(thakis): Can probably remove this and --if-needed altogether.
     if re.search(r'\b(make_clang_dir)=', os.environ.get('GYP_DEFINES', '')):
       print 'Skipping Clang update (make_clang_dir= was set in GYP_DEFINES).'
       return 0