CHECK that all frames in a stack trace are present

This CL introduces a CHECK to narrow down the cause for a crash
happening in the wild, but that currently has no reproduction case.

Bug: chromium:1035651
Change-Id: I61c0658d4b753f2c7d12aa8e20d5a2ff69594d1d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1985989Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65592}

src/inspector/v8-debugger.cc

@@ -1073,6 +1073,7 @@ void V8Debugger::collectOldAsyncStacksIfNeeded() {
 
 std::shared_ptr<StackFrame> V8Debugger::symbolize(
     v8::Local<v8::StackFrame> v8Frame) {
+  CHECK(!v8Frame.IsEmpty());
   auto it = m_framesCache.end();
   int frameId = 0;
   if (m_maxAsyncCallStackDepth) {