Make workers inherit the large heap limit of the main isolate.

third_party/WebKit/Source/bindings/core/v8/WorkerV8Settings.h

Index: third_party/WebKit/Source/bindings/core/v8/WorkerV8Settings.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/WorkerV8Settings.h b/third_party/WebKit/Source/bindings/core/v8/WorkerV8Settings.h
new file mode 100644
index 0000000000000000000000000000000000000000..6dc5676c9be9d2ddae4ec3615c0a4dc1b48f955a
--- /dev/null
+++ b/third_party/WebKit/Source/bindings/core/v8/WorkerV8Settings.h
@@ -0,0 +1,26 @@
+// Copyright 2017 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 WorkerV8Settings_h
+#define WorkerV8Settings_h
+
+#include "bindings/core/v8/V8CacheOptions.h"
+#include "core/CoreExport.h"
+
+namespace blink {
+
+// The V8 settings that are passed from the main isolate to the worker isolate.
+struct CORE_EXPORT WorkerV8Settings {
+  enum class HeapLimitMode { Default, IncreasedForDebugging };
+  WorkerV8Settings(HeapLimitMode heapLimitMode, V8CacheOptions v8CacheOptions)
+      : m_heapLimitMode(heapLimitMode), m_v8CacheOptions(v8CacheOptions) {}
+  static WorkerV8Settings Default() {
+    return WorkerV8Settings(HeapLimitMode::Default, V8CacheOptionsDefault);
+  }
+  HeapLimitMode m_heapLimitMode;
+  V8CacheOptions m_v8CacheOptions;
+};
+
+}  // namespace blink
+#endif  // WorkerV8Setttings