[Android] Add GinJavaBridgeValue for Gin Java Bridge

content/common/android/gin_java_bridge_value.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 CONTENT_COMMON_ANDROID_GIN_JAVA_BRIDGE_VALUE_H_
+#define CONTENT_COMMON_ANDROID_GIN_JAVA_BRIDGE_VALUE_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/pickle.h"
+#include "base/values.h"
+#include "content/common/content_export.h"
+
+// In Java Bridge, we need to pass some kinds of values that can't
+// be put into base::Value. And since base::Value is not extensible,
+// we transfer these special values via base::BinaryValue.
+
+namespace content {
+
+class GinJavaBridgeValue {
+ public:
+  enum Type {
+    TYPE_FIRST_VALUE = 0,
+    // JavaScript 'undefined'
+    TYPE_UNDEFINED = 0,
+    // JavaScript NaN and Infinity
+    TYPE_NONFINITE,
+    // Bridge Object ID
+    TYPE_OBJECT_ID,
+    TYPE_LAST_VALUE
+  };
+
+  // Serialization
+  CONTENT_EXPORT static scoped_ptr<base::BinaryValue> CreateUndefinedValue();
+  CONTENT_EXPORT static scoped_ptr<base::BinaryValue> CreateNonFiniteValue(
+      float in_value);
+  CONTENT_EXPORT static scoped_ptr<base::BinaryValue> CreateNonFiniteValue(
+      double in_value);
+  CONTENT_EXPORT static scoped_ptr<base::BinaryValue> CreateObjectIDValue(
+      int32 in_value);
+
+  // De-serialization
+  CONTENT_EXPORT static bool ContainsGinJavaBridgeValue(
+      const base::Value* value);
+  CONTENT_EXPORT static scoped_ptr<const GinJavaBridgeValue> FromValue(
+      const base::Value* value);
+
+  CONTENT_EXPORT Type GetType() const;
+  CONTENT_EXPORT bool IsType(Type type) const;
+
+  CONTENT_EXPORT bool GetAsNonFinite(float* out_value) const;
+  CONTENT_EXPORT bool GetAsObjectID(int32* out_object_id) const;
+
+ private:
+  explicit GinJavaBridgeValue(Type type);
+  explicit GinJavaBridgeValue(const base::BinaryValue* value);
+  base::BinaryValue* SerializeToBinaryValue();
+
+  Pickle pickle_;
+
+  DISALLOW_COPY_AND_ASSIGN(GinJavaBridgeValue);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_ANDROID_GIN_JAVA_BRIDGE_VALUE_H_