Bug 1510919 - Make mach clang-format support .cc files r=andi

Differential Revision: https://phabricator.services.mozilla.com/D13372

--HG--
extra : moz-landing-system : lando

python/mozbuild/mozbuild/mach_commands.py

@@ -1648,7 +1648,7 @@ class StaticAnalysis(MachCommandBase):
     """Utilities for running C++ static analysis checks and format."""
 
     # List of file extension to consider (should start with dot)
-    _format_include_extensions = ('.cpp', '.c', '.h', '.java')
+    _format_include_extensions = ('.cpp', '.c', '.cc', '.h', '.java')
     # File contaning all paths to exclude from formatting
     _format_ignore_file = '.clang-format-ignore'