Add TODOs for broken build code in aggregate_vector_icons.

ui/gfx/vector_icons/aggregate_vector_icons.py

Index: ui/gfx/vector_icons/aggregate_vector_icons.py
diff --git a/ui/gfx/vector_icons/aggregate_vector_icons.py b/ui/gfx/vector_icons/aggregate_vector_icons.py
index 72fbc11cc935891429ad50d5af4dcd4165131706..938f1a858fd15fffdf4a870c4045562cca17a52d 100644
--- a/ui/gfx/vector_icons/aggregate_vector_icons.py
+++ b/ui/gfx/vector_icons/aggregate_vector_icons.py
@@ -9,6 +9,10 @@ import os
 import textwrap
 
 
+# TODO(brettw) bug 535386: This should not take a directory as an input, but
+# rather a response file listing the inputs or sometimes the build will be
+# incorrect.
+
 def AggregateVectorIcons(working_directory, output_cc, output_h):
   """Compiles all .icon files in a directory into two C++ files.