[inspector] speculative avoid using debugger context as current in blink

src/inspector/v8-debugger.cc

 // Copyright 2016 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/v8-debugger.h"
 
 #include "src/inspector/debugger-script.h"
 #include "src/inspector/inspected-context.h"
 #include "src/inspector/protocol/Protocol.h"
 #include "src/inspector/script-breakpoint.h"
@@ skipping 470 matching lines @@
   }
 
   m_pausedContext = pausedContext;
   m_executionState = executionState;
   V8DebuggerAgentImpl::SkipPauseRequest result = agent->didPause(
       pausedContext, exception, breakpointIds, isPromiseRejection, isUncaught);
   if (result == V8DebuggerAgentImpl::RequestNoSkip) {
     m_runningNestedMessageLoop = true;
     int groupId = m_inspector->contextGroupId(pausedContext);
     DCHECK(groupId);
+    v8::Context::Scope scope(pausedContext);
+    v8::Local<v8::Context> context = m_isolate->GetCurrentContext();
+    CHECK(!context.IsEmpty() &&
+          context != v8::Debug::GetDebugContext(m_isolate));
     m_inspector->client()->runMessageLoopOnPause(groupId);
     // The agent may have been removed in the nested loop.
     agent = m_inspector->enabledDebuggerAgentForGroup(
         m_inspector->contextGroupId(pausedContext));
     if (agent) agent->didContinue();
     m_runningNestedMessageLoop = false;
   }
   m_pausedContext.Clear();
   m_executionState.Clear();
 
@@ skipping 497 matching lines @@
 
   size_t stackSize =
       fullStack ? V8StackTraceImpl::maxCallStackSizeToCapture : 1;
   if (m_inspector->enabledRuntimeAgentForGroup(contextGroupId))
     stackSize = V8StackTraceImpl::maxCallStackSizeToCapture;
 
   return V8StackTraceImpl::capture(this, contextGroupId, stackSize);
 }
 
 }  // namespace v8_inspector