Add simple trace logging of received IPC messages

chrome/tools/ipclist/ipclist.cc

Index: chrome/tools/ipclist/ipclist.cc
diff --git a/chrome/tools/ipclist/ipclist.cc b/chrome/tools/ipclist/ipclist.cc
index 9a2faabe49dbf91c14e76fe09647b7242b42400d..419a05b6381712b6ba82ea88a8dd354d92037a63 100644
--- a/chrome/tools/ipclist/ipclist.cc
+++ b/chrome/tools/ipclist/ipclist.cc
@@ -38,10 +38,11 @@ static bool check_msgtable() {
   int highest_class_id = 0;
   std::vector<int> exemptions;
 
-  // Exclude test files from consideration.  Do not include message
-  // files used inside the actual chrome browser in this list.
+  // Exclude test and other non-browser files from consideration.  Do not
+  // include message files used inside the actual chrome browser in this list.
   exemptions.push_back(TestMsgStart);
   exemptions.push_back(FirefoxImporterUnittestMsgStart);
+  exemptions.push_back(ShellMsgStart);
 
   for (size_t i = 0; i < MSGTABLE_SIZE; ++i) {
     int class_id = IPC_MESSAGE_ID_CLASS(msgtable[i].id);
@@ -64,9 +65,15 @@ static bool check_msgtable() {
       highest_class_id = class_id;
   }
 
-  if (LastIPCMsgStart > highest_class_id + 1) {
+  while (LastIPCMsgStart > highest_class_id + 1) {
+    std::vector<int>::iterator iter;
+    iter = find(exemptions.begin(), exemptions.end(), highest_class_id+1);
+    if (iter == exemptions.end()) {
       std::cout << "Missing message file: gap before LastIPCMsgStart\n";
       result = false;
+      break;
+    }
+    ++highest_class_id;
   }
 
   if (!result)