My clang now doesn't complain about !"foo".

tools/flags/SkCommandLineFlags.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCommandLineFlags.h"
 #include "SkTDArray.h"
 
@@ skipping 260 matching lines @@
                             break;
                         case SkFlagInfo::kInt_FlagType:
                             i++;
                             flag->setInt(atoi(argv[i]));
                             break;
                         case SkFlagInfo::kDouble_FlagType:
                             i++;
                             flag->setDouble(atof(argv[i]));
                             break;
                         default:
-                            SkASSERT(!"Invalid flag type");
+                            SkDEBUGFAIL("Invalid flag type");
                     }
                     break;
                 }
                 flag = flag->next();
             }
             if (!flagMatched) {
                 SkDebugf("Got unknown flag \"%s\". Exiting.\n", argv[i]);
                 exit(-1);
             }
         }
@@ skipping 35 matching lines @@
         if (matchStart ? (!matchEnd || matchLen == testLen)
                 && strncmp(name, matchName, matchLen) == 0
                 : matchEnd ? matchLen <= testLen
                 && strncmp(name + testLen - matchLen, matchName, matchLen) == 0
                 : strstr(name, matchName) != 0) {
             return matchExclude;
         }
     }
     return !anyExclude;
 }