Move IPC fuzzer switches and helpers from chrome/common to content/common.

chrome/chrome_common.gypi

Index: chrome/chrome_common.gypi
diff --git a/chrome/chrome_common.gypi b/chrome/chrome_common.gypi
index 196c2179ac74e743baa241e54c0bec77a1dabaa4..880a69f6232c0be234e9cf11fde28fcb46392c57 100644
--- a/chrome/chrome_common.gypi
+++ b/chrome/chrome_common.gypi
@@ -269,10 +269,6 @@
       'common/importer/safari_importer_utils.h',
       'common/importer/safari_importer_utils.mm',
     ],
-    'chrome_common_ipc_fuzzer_sources': [
-      'common/external_ipc_dumper.cc',
-      'common/external_ipc_dumper.h',
-    ],
     'chrome_common_service_process_sources': [
       'common/service_messages.h',
       'common/service_process_util.cc',
@@ -462,9 +458,6 @@
             '<(DEPTH)/components/nacl.gyp:nacl_common',
           ],
         }],
-        ['enable_ipc_fuzzer==1', {
-          'sources': [ '<@(chrome_common_ipc_fuzzer_sources)' ],
-        }],
         ['enable_plugins==1', {
           'dependencies': [
             '<(DEPTH)/third_party/adobe/flash/flash_player.gyp:flapper_version_h',