[inspector] provide more usefull error message for non serializable value

src/inspector/V8DebuggerAgentImpl.cpp

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/inspector/V8DebuggerAgentImpl.h"
 
 #include "src/inspector/InjectedScript.h"
 #include "src/inspector/InspectedContext.h"
 #include "src/inspector/JavaScriptCallFrame.h"
 #include "src/inspector/RemoteObjectId.h"
@@ skipping 996 matching lines @@
     }
 
     if (hasInternalError(errorString,
                          !objects->Set(debuggerContext, frameOrdinal, details)
                               .FromMaybe(false)))
       return Array<CallFrame>::create();
   }
 
   protocol::ErrorSupport errorSupport;
   std::unique_ptr<Array<CallFrame>> callFrames = Array<CallFrame>::parse(
-      toProtocolValue(debuggerContext, objects).get(), &errorSupport);
+      toProtocolValue(errorString, debuggerContext, objects).get(),

[dgozman, 2016/09/19 17:35:06]

Should check the result of toProtocolValue and return it's errorString.

[kozy, 2016/09/20 15:34:27]

Done.

+      &errorSupport);
   if (hasInternalError(errorString, !callFrames))
     return Array<CallFrame>::create();
   return callFrames;
 }
 
 std::unique_ptr<StackTrace> V8DebuggerAgentImpl::currentAsyncStackTrace() {
   if (m_pausedContext.IsEmpty()) return nullptr;
   V8StackTraceImpl* stackTrace = m_debugger->currentAsyncCallChain();
   return stackTrace ? stackTrace->buildInspectorObjectForTail(m_debugger)
                     : nullptr;
@@ skipping 213 matching lines @@
 
 void V8DebuggerAgentImpl::reset() {
   if (!enabled()) return;
   m_scheduledDebuggerStep = NoStep;
   m_scripts.clear();
   m_blackboxedPositions.clear();
   m_breakpointIdToDebuggerBreakpointIds.clear();
 }
 
 }  // namespace v8_inspector