ipc_message_util: support multiple input files. All input files are concatenated before filtering.
Start building all targets in mutate.gyp/replay.gyp with the ipc_fuzzer target.

BUG=260848

Review URL: https://codereview.chromium.org/143593002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246043 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246043
IPC fuzzer: add remove_close_messages.py utility that removes ViewHostMsg_Close and alike from testcases. Filtering out close messages stops the browser from exiting early during corpus distillation.

BUG=260848

Review URL: https://codereview.chromium.org/131833008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246044 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246044