Support merged Dart-JS callstacks

Source/bindings/v8/V8RecursionScope.cpp

Index: Source/bindings/v8/V8RecursionScope.cpp
diff --git a/Source/bindings/v8/V8RecursionScope.cpp b/Source/bindings/v8/V8RecursionScope.cpp
index ab09a3b70d3bd1ec6c8d96bd238075d32a0784e5..9d0489248a5c952f315f18f0709d68ee9a75c661 100644
--- a/Source/bindings/v8/V8RecursionScope.cpp
+++ b/Source/bindings/v8/V8RecursionScope.cpp
@@ -32,6 +32,8 @@
 #include "bindings/v8/V8RecursionScope.h"
 
 #include "core/dom/Microtask.h"
+#include "core/inspector/InspectorInstrumentation.h"
+#include "core/inspector/ScriptCallStack.h"
 #include "modules/indexeddb/IDBPendingTransactionMonitor.h"
 
 namespace WebCore {
@@ -45,4 +47,17 @@ void V8RecursionScope::didLeaveScriptContext()
     IDBPendingTransactionMonitor::from(*m_executionContext).deactivateNewTransactions();
 }
 
+void V8RecursionScope::trackStackDepth(V8PerIsolateData* isolateData)
+{
+    StackTraceTimestampTracker* tracker = isolateData->stackTraceTimestampTracker();
+    // FIXMEDART: implement a more efficient way to measure the current V8
+    // stack trace depth than calling v8::StackTrace::CurrentStackTrace.
+    // The current implementation will not slow down V8 when the
+    // devtools are closed but could have a significant performance impact
+    // when the devtools are open for code that dispatches a lot of synchronous
+    // messages or relies heavily on Dart-JS interop.
+    tracker->incrementRecursionLevel(InspectorInstrumentation::hasFrontends() && tracker->recursionLevel() > 0 ?
+        v8::StackTrace::CurrentStackTrace(m_isolate, ScriptCallStack::maxCallStackSizeToCapture)->GetFrameCount() : 0);
+}
+
 } // namespace WebCore