Add src root support for chromium_src overrides.

script/redirect-cc.py

@@ -9,6 +9,7 @@ IS_WIN32 = sys.platform == 'win32'
 
 def main():
     args = sys.argv[1:]
+    append_root_src_include(args)
     brave_path = replace_cc_arg(args)
     if 'CC_WRAPPER' in os.environ:
         args = [os.environ['CC_WRAPPER']] + args
@@ -22,6 +23,13 @@ def main():
     return cc_retcode
 
 
+def append_root_src_include(args):
+  for arg in args:
+    if arg.startswith('-I') and arg.endswith('brave/chromium_src'):
+        args.append(arg + '/../../..')
+        return
+
+
 def replace_cc_arg(args):
     # Interested in -c <path>.cc
     try: