gpu: Do not relaunch the process during teardown.

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index 7aec4ef6a28854661773fd50d952d8804f95ca69..e03b045e0eee07e16141d7d3daeb2882e9d48084 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -369,6 +369,10 @@ GpuProcessHost* GpuProcessHost::Get(GpuProcessKind kind, bool force_create) {
   if (!force_create)
     return nullptr;
 
+  // Do not create a new process if browser is shutting down.
+  if (BrowserMainRunner::ExitedMainMessageLoop())
+    return nullptr;
+
   static int last_host_id = 0;
   int host_id;
   host_id = ++last_host_id;