[Extensions] Add crash tracking

extensions/browser/sandboxed_unpacker.cc

Index: extensions/browser/sandboxed_unpacker.cc
diff --git a/extensions/browser/sandboxed_unpacker.cc b/extensions/browser/sandboxed_unpacker.cc
index 9c2746a1309754136e2284b242b18cf2167084b8..649a48ca399670d36ac7d9684f64a296c3dbe6f8 100644
--- a/extensions/browser/sandboxed_unpacker.cc
+++ b/extensions/browser/sandboxed_unpacker.cc
@@ -228,7 +228,12 @@ SandboxedUnpacker::SandboxedUnpacker(
       location_(location),
       creation_flags_(creation_flags),
       unpacker_io_task_runner_(unpacker_io_task_runner),
-      utility_wrapper_(new UtilityHostWrapper) {}
+      utility_wrapper_(new UtilityHostWrapper) {
+  // Tracking for crbug.com/692069. The location must be valid. If it's invalid,
+  // the utility process kills itself for a bad IPC.
+  CHECK_GT(location, Manifest::INVALID_LOCATION);
+  CHECK_LT(location, Manifest::NUM_LOCATIONS);
+}
 
 bool SandboxedUnpacker::CreateTempDirectory() {
   CHECK(unpacker_io_task_runner_->RunsTasksOnCurrentThread());