Add whitelist support for grit repack steps.

tools/resources/find_used_resources.py

Index: tools/resources/find_used_resources.py
diff --git a/tools/resources/find_used_resources.py b/tools/resources/find_used_resources.py
index 60af3e5197f1a10d3dfd1ff6d96c156876a18f35..3fc3bcef33920ab2188e2fa28e9702cc7a06be66 100755
--- a/tools/resources/find_used_resources.py
+++ b/tools/resources/find_used_resources.py
@@ -18,7 +18,8 @@ script parses out the list of used resource ids. These resource ids show up in
 the build output after building Chrome with gyp variable
 enable_resource_whitelist_generation set to 1. This gyp flag causes the compiler
 to print out a UnknownPragma message every time a resource id is used. E.g.:
-foo.cc:22:0: warning: ignoring #pragma IDS_FOO_BAR  [-Wunknown-pragmas]
+foo.cc:22:0: warning: ignoring #pragma whitelisted_resource_12345
+[-Wunknown-pragmas]
 
 """
 
@@ -29,7 +30,7 @@ def GetResourceIdsInPragmaWarnings(input):
   """
   used_resources = set()
   unknown_pragma_warning_pattern = re.compile('warning: ignoring #pragma '
-      '(?P<resource_id>[A-Z0-9_]*)  \[-Wunknown-pragmas\]')
+      'whitelisted_resource_(?P<resource_id>[0-9]*)  \[-Wunknown-pragmas\]')
   for ln in input:
     match = unknown_pragma_warning_pattern.search(ln)
     if match: