[inspector] deduplicate stack frames

src/inspector/v8-debugger.cc

Index: src/inspector/v8-debugger.cc
diff --git a/src/inspector/v8-debugger.cc b/src/inspector/v8-debugger.cc
index fd8c93ca9026e94bc0953d4713d10c893d69694f..d093f28d287b6198a358f0319dba77e19d615fe2 100644
--- a/src/inspector/v8-debugger.cc
+++ b/src/inspector/v8-debugger.cc
@@ -1031,6 +1031,11 @@ void V8Debugger::collectOldAsyncStacksIfNeeded() {
     parentLeft.insert(it);
   }
   m_parentTask.swap(parentLeft);
+  std::map<int, std::weak_ptr<StackFrame>> framesCache;
+  for (auto it : m_framesCache) {
+    if (!it.second.expired()) framesCache.insert(it);
+  }
+  m_framesCache.swap(framesCache);
 }
 
 void V8Debugger::removeOldAsyncTasks(AsyncTaskToStackTrace& map) {
@@ -1041,6 +1046,16 @@ void V8Debugger::removeOldAsyncTasks(AsyncTaskToStackTrace& map) {
   map.swap(cleanCopy);
 }
 
+std::shared_ptr<StackFrame> V8Debugger::lookupFrame(int frameId) {
+  auto it = m_framesCache.find(frameId);
+  if (it != m_framesCache.end()) return it->second.lock();
+  return nullptr;
+}
+
+void V8Debugger::storeFrame(int frameId, std::shared_ptr<StackFrame> frame) {
+  m_framesCache[frameId] = frame;
+}
+
 void V8Debugger::setMaxAsyncTaskStacksForTest(int limit) {
   m_maxAsyncCallStacks = 0;
   collectOldAsyncStacksIfNeeded();