Fix a case 'submatched_dict' may include a key with None value.

BUG=None
NOTRY=True
TBR=peria@chromium.org

Review URL: https://codereview.chromium.org/15948004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202808 0039d316-1c4b-4281-b951-d872f2087c98

tools/deep_memory_profiler/dmprof.py

@@ -1036,13 +1036,13 @@ class Dump(object):
 
       submatched_dict = submatched.groupdict()
       region_info = { 'vma': current_vma }
-      if 'TYPE' in submatched_dict:
+      if submatched_dict.get('TYPE'):
         region_info['type'] = submatched_dict['TYPE'].strip()
-      if 'COMMITTED' in submatched_dict:
+      if submatched_dict.get('COMMITTED'):
         region_info['committed'] = int(submatched_dict['COMMITTED'])
-      if 'RESERVED' in submatched_dict:
+      if submatched_dict.get('RESERVED'):
         region_info['reserved'] = int(submatched_dict['RESERVED'])
-      if 'BUCKETID' in submatched_dict:
+      if submatched_dict.get('BUCKETID'):
         region_info['bucket_id'] = int(submatched_dict['BUCKETID'])
 
       self._map[(int(matched.group(2), 16),