Bug 1578422: MOZ_DIAGNOSTIC_ASSERT when shared memory setup fails in CrashReporterClient::InitSingleton. r=gsvelto

This will help to catch changes that cause a loss of annotations without
affecting Release or Beta.
This also makes CrashReporterClient::InitSingleton return void as the previous
bool was ignored in all cases.

Differential Revision: https://phabricator.services.mozilla.com/D44642

--HG--
extra : moz-landing-system : lando

ipc/glue/CrashReporterClient.h

@@ -7,6 +7,7 @@
 #ifndef mozilla_ipc_CrashReporterClient_h
 #define mozilla_ipc_CrashReporterClient_h
 
+#include "mozilla/Assertions.h"
 #include "mozilla/StaticMutex.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/Unused.h"
@@ -30,21 +31,21 @@ class CrashReporterClient {
   // somewhere, and when the top-level actor's ActorDestroy runs (or when the
   // crash reporter needs metadata), the shmem should be parsed.
   template <typename T>
-  static bool InitSingleton(T* aToplevelProtocol) {
+  static void InitSingleton(T* aToplevelProtocol) {
     // The crash reporter is not enabled in recording/replaying processes.
     if (recordreplay::IsRecordingOrReplaying()) {
-      return true;
+      return;
     }
 
     Shmem shmem;
     if (!AllocShmem(aToplevelProtocol, &shmem)) {
-      return false;
+      MOZ_DIAGNOSTIC_ASSERT(false, "failed to allocate crash reporter shmem");
+      return;
     }
 
     InitSingletonWithShmem(shmem);
     Unused << aToplevelProtocol->SendInitCrashReporter(
         std::move(shmem), CrashReporter::CurrentThreadId());
-    return true;
   }
 
   template <typename T>