Unbreak clang-format / GetBuildtoolsPlatformBinaryPath() after depot_tools/+/1512058

TBR=tandrii
Bug: 939959
Change-Id: Ia200eb38fda3d2572c4f1c3dc0d9f8f8fbd34362
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1515874
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>

gclient_paths.py

@@ -106,6 +106,7 @@ def GetBuildtoolsPlatformBinaryPath():
   if not buildtools_path:
     return None
 
+  import sys
   if sys.platform.startswith(('cygwin', 'win')):
     subdir = 'win'
   elif sys.platform == 'darwin':
@@ -119,6 +120,7 @@ def GetBuildtoolsPlatformBinaryPath():
 
 def GetExeSuffix():
   """Returns '' or '.exe' depending on how executables work on this platform."""
+  import sys
   if sys.platform.startswith(('cygwin', 'win')):
     return '.exe'
   return ''