Support merged Dart-JS callstacks

Source/bindings/v8/V8RecursionScope.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #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 {
 
 void V8RecursionScope::didLeaveScriptContext()
 {
     Microtask::performCheckpoint();
 
     // Indexed DB requires that transactions are created with an internal |active| flag
     // set to true, but the flag becomes false when control returns to the event loop.
     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