Replace ASSERT with DCHECK in core/

third_party/WebKit/Source/core/streams/UnderlyingSourceBase.cpp

 // Copyright 2016 The Chromium 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 "core/streams/UnderlyingSourceBase.h"
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "core/streams/ReadableStreamController.h"
 #include "platform/bindings/ScriptState.h"
 #include "v8/include/v8.h"
 
 namespace blink {
 
 ScriptPromise UnderlyingSourceBase::startWrapper(ScriptState* script_state,
                                                  ScriptValue js_controller) {
   // Cannot call start twice (e.g., cannot use the same UnderlyingSourceBase to
   // construct multiple streams).
-  ASSERT(!controller_);
+  DCHECK(!controller_);
 
   controller_ = new ReadableStreamController(js_controller);
 
   return Start(script_state);
 }
 
 ScriptPromise UnderlyingSourceBase::Start(ScriptState* script_state) {
   return ScriptPromise::CastUndefined(script_state);
 }
 
@@ skipping 34 matching lines @@
     controller_.Clear();
   }
 }
 
 DEFINE_TRACE(UnderlyingSourceBase) {
   ContextLifecycleObserver::Trace(visitor);
   visitor->Trace(controller_);
 }
 
 }  // namespace blink