inspector: handle spurious wakeups in InspectorIo startup

The constructor waited on thread_start_condition_ without a
predicate, so a spurious wakeup could let it return before the IO
thread assigned request_queue_, leading to a null dereference in
Start(). Loop until request_queue_ is set.

Signed-off-by: Aaron Lichtman <alichtman@meta.com>

Author: alichtman

src/inspector_io.cc

@@ -268,7 +268,8 @@ InspectorIo::InspectorIo(std::shared_ptr<MainThreadHandle> main_thread,
       id_(GenerateID()) {
   Mutex::ScopedLock scoped_lock(thread_start_lock_);
   CHECK_EQ(uv_thread_create(&thread_, InspectorIo::ThreadMain, this), 0);
-  thread_start_condition_.Wait(scoped_lock);
+  while (request_queue_ == nullptr)
+    thread_start_condition_.Wait(scoped_lock);
 }
 
 InspectorIo::~InspectorIo() {