Update from https://crrev.com/333737

tools/clang/scripts/run_tool.py

Index: tools/clang/scripts/run_tool.py
diff --git a/tools/clang/scripts/run_tool.py b/tools/clang/scripts/run_tool.py
index 58a9a86570c6b3b203d5a0004ce56d04426db314..56cd5d24f8be2f400190136d9705972f9fb1e6c4 100755
--- a/tools/clang/scripts/run_tool.py
+++ b/tools/clang/scripts/run_tool.py
@@ -315,13 +315,14 @@ def main(argv):
 
   if len(argv) == 3 and argv[2] == '--all':
     filenames = set(_GetFilesFromCompileDB(argv[1]))
+    source_filenames = filenames
   else:
     filenames = set(_GetFilesFromGit(argv[2:]))
     # Filter out files that aren't C/C++/Obj-C/Obj-C++.
     extensions = frozenset(('.c', '.cc', '.m', '.mm'))
-    filenames = [f for f in filenames
-                 if os.path.splitext(f)[1] in extensions]
-  dispatcher = _CompilerDispatcher(argv[0], argv[1], filenames)
+    source_filenames = [f for f in filenames
+                        if os.path.splitext(f)[1] in extensions]
+  dispatcher = _CompilerDispatcher(argv[0], argv[1], source_filenames)
   dispatcher.Run()
   # Filter out edits to files that aren't in the git repository, since it's not
   # useful to modify files that aren't under source control--typically, these