[Android] Add messages for Gin Java Bridge implementation

content/common/gin_java_bridge_messages.h

+// Copyright (c) 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.
+
+// IPC messages for injected Java objects (Gin-based implementation).
+
+// Multiply-included message file, hence no include guard.
+
+#include "base/basictypes.h"
+#include "content/common/content_export.h"
+#include "ipc/ipc_message_macros.h"
+
+#undef IPC_MESSAGE_EXPORT
+#define IPC_MESSAGE_EXPORT CONTENT_EXPORT
+#define IPC_MESSAGE_START GinJavaBridgeMsgStart
+
+// Messages for handling Java objects injected into JavaScript -----------------
+
+// Sent from browser to renderer to add a Java object with the given name.
+// Object IDs are generated on the browser side.
+IPC_MESSAGE_ROUTED2(GinJavaBridgeMsg_AddNamedObject,
+                    std::string /* name */,
+                    int32 /* object_id */)
+
+// Sent from browser to renderer to remove a Java object with the given name.
+IPC_MESSAGE_ROUTED1(GinJavaBridgeMsg_RemoveNamedObject,
+                    std::string /* name */)
+
+// Sent from renderer to browser to get information about methods of
+// the given object. The query will only succeed if inspection of injected
+// objects is enabled on the browser side.
+IPC_SYNC_MESSAGE_ROUTED1_1(GinJavaBridgeHostMsg_GetMethods,
+                           int32 /* object_id */,
+                           std::set<std::string> /* returned_method_names */)
+
+// Sent from renderer to browser to find out, if an object has a method with
+// the given name.
+IPC_SYNC_MESSAGE_ROUTED2_1(GinJavaBridgeHostMsg_HasMethod,
+                           int32 /* object_id */,
+                           std::string /* method_name */,
+                           bool /* result */)
+
+// Sent from renderer to browser to invoke a method. Method arguments
+// are chained into |arguments| list. base::ListValue is used for |result| as
+// a container to work around immutability of base::Value.
+// Empty result list indicates that an error has happened on the Java side
+// (either bridge-induced error or an unhandled Java exception) and an exception
+// must be thrown into JavaScript.
+// Some special value types that are not supported by base::Value are encoded
+// as BinaryValues via GinJavaBridgeValue.
+IPC_SYNC_MESSAGE_ROUTED3_1(GinJavaBridgeHostMsg_InvokeMethod,
+                           int32 /* object_id */,
+                           std::string /* method_name */,
+                           base::ListValue /* arguments */,
+                           base::ListValue /* result */)
+
+// Sent from renderer to browser in two cases:
+//
+//  1. (Main usage) To inform that the JS wrapper of the object has
+//     been completely dereferenced and garbage-collected.
+//
+//  2. To notify the browser that wrapper creation has failed.  The browser side
+//     assumes optimistically that every time an object is returned from a
+//     method, the corresponding wrapper object will be successfully created on
+//     the renderer side. Sending of this message informs the browser whether
+//     this expectation has failed.
+IPC_MESSAGE_ROUTED1(GinJavaBridgeHostMsg_ObjectWrapperDeleted,
+                    int32 /* object_id */)