[Extensions Bindings] Support ArrayBufferView in idl files

chrome/common/extensions/api/idltest.idl

 // Copyright 2013 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.
 
 // An API to test IDL schema specifications.
 namespace idltest {
 
   callback LongArrayCallback = void(long[] array);
   callback ArrayBufferCallback = void(ArrayBuffer buffer);
 
   interface Functions {
     // Functions for testing binary data request/response parameters. The first
     // two just return back the bytes they were passed in an array.
     static void sendArrayBuffer(ArrayBuffer input, LongArrayCallback cb);
 
     // TODO(asargent) - we currently can't have [instanceOf=ArrayBufferView],
     // I think because ArrayBufferView isn't an instantiable type. The best
     // we might be able to do is have a 'choices' list including all the
     // typed array subclasses like Uint8Array, Uint16Array, Float32Array, etc.
-    static void sendArrayBufferView([instanceOf=Uint8Array] object input,
-                                    LongArrayCallback cb);
+    static void sendArrayBufferView(
+        [instanceOf=Uint8Array] ArrayBufferView input,

[Devlin, 2017/06/22 21:54:57]

We could actually just remove this [instanceOf] and only add it when necessary,
but that's orthogonal to this change.

+        LongArrayCallback cb);
     static void getArrayBuffer(ArrayBufferCallback cb);
 
     // This function should not have C++ code autogenerated (the variable name
     // |switch| should cause compile errors if it does). But the name should
     // get defined and made visible from within extensions/apps code.
     [nocompile] static void nocompileFunc(long switch);
 
     // This function should not have C++ code autogenerated (the variable name
     // |switch| should cause compile errors if it does). The name should also
     // never be defined in Javascript and invisible to extensions/apps code.
     [nodefine] static void nodefineFunc(long switch);
   };
 
 };