Oilpan: have DOMException be on the heap by default.

Source/core/streams/ReadableStreamImpl.h

 // Copyright 2014 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.
 
 #ifndef ReadableStreamImpl_h
 #define ReadableStreamImpl_h
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
@@ skipping 130 matching lines @@
 
     void resolveAllPendingReadsAsDone() override
     {
         for (auto& resolver : m_pendingReads) {
             ScriptState::Scope scope(resolver->scriptState());
             resolver->resolve(v8IteratorResultDone(resolver->scriptState()));
         }
         m_pendingReads.clear();
     }
 
-    void rejectAllPendingReads(PassRefPtrWillBeRawPtr<DOMException> r) override
+    void rejectAllPendingReads(DOMException* reason) override
     {
-        RefPtrWillBeRawPtr<DOMException> reason = r;
         for (auto& resolver : m_pendingReads)
             resolver->reject(reason);
         m_pendingReads.clear();
     }
 
     bool shouldApplyBackpressure() override
     {
         return m_strategy->shouldApplyBackpressure(m_totalQueueSize, this);
     }
     bool hasPendingReads() const override { return !m_pendingReads.isEmpty(); }
@@ skipping 54 matching lines @@
     ASSERT(queue.isEmpty());
 
     queue.swap(m_queue);
     m_totalQueueSize = 0;
     readInternalPostAction();
 }
 
 } // namespace blink
 
 #endif // ReadableStreamImpl_h