Remove two unused ipc_message_start.h constants

SurfaceViewManagerMsgStart obsolete in f7df5b34.
PeerConnectionTrackerMsgStart obsolete in bc917af8.

Change-Id: I275f10fe0e1d66b427ca55f96223ed22d7b06ae0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1888382Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710521}

ipc/ipc_message_start.h

@@ -35,7 +35,6 @@ enum IPCMessageStart {
   ChromotingMsgStart,
   BrowserPluginMsgStart,
   AndroidWebViewMsgStart,
-  PeerConnectionTrackerMsgStart,
   NaClHostMsgStart,
   EncryptedMediaMsgStart,
   CastMsgStart,
@@ -48,7 +47,6 @@ enum IPCMessageStart {
   GuestViewMsgStart,
   IPCTestMsgStart,
   MediaPlayerDelegateMsgStart,
-  SurfaceViewManagerMsgStart,
   ExtensionWorkerMsgStart,
   SubresourceFilterMsgStart,
   UnfreezableFrameMsgStart,

tools/ipc_fuzzer/message_tools/message_list.cc

@@ -63,7 +63,6 @@ static bool check_msgtable() {
   exemptions.push_back(GinJavaBridgeMsgStart);
   exemptions.push_back(AndroidWebViewMsgStart);
   exemptions.push_back(ExtensionWorkerMsgStart);
-  exemptions.push_back(SurfaceViewManagerMsgStart);
 #endif  // !defined(OS_ANDROID)
 
 #if !defined(USE_OZONE)