Bug 1654477 P4: Add pref to crash the browser if the GPU process crashes for testing. r=jrmuizel

Differential Revision: https://phabricator.services.mozilla.com/D93673

gfx/ipc/GPUProcessManager.cpp

@@ -555,6 +555,10 @@ void GPUProcessManager::NotifyListenersOnCompositeDeviceReset() {
 void GPUProcessManager::OnProcessUnexpectedShutdown(GPUProcessHost* aHost) {
   MOZ_ASSERT(mProcess && mProcess == aHost);
 
+  if (StaticPrefs::layers_gpu_process_crash_also_crashes_browser()) {
+    MOZ_CRASH("GPU process crashed and pref is set to crash the browser.");
+  }
+
   CompositorManagerChild::OnGPUProcessLost(aHost->GetProcessToken());
   DestroyProcess();
 

modules/libpref/init/StaticPrefList.yaml

@@ -5430,6 +5430,11 @@
   value: 5000
   mirror: once
 
+- name: layers.gpu-process.crash-also-crashes-browser
+  type: bool
+  value: false
+  mirror: always
+
 - name: layers.low-precision-buffer
   type: RelaxedAtomicBool
   value: false