[Extensions Bindings] Support ArrayBufferView in idl files

chrome/common/extensions/api/idltest.idl

Index: chrome/common/extensions/api/idltest.idl
diff --git a/chrome/common/extensions/api/idltest.idl b/chrome/common/extensions/api/idltest.idl
index 4bb0ab5e0a4aeffcc3082dc4b2303efd7d7d4be9..03b21d4b005900e3aa52ef5ec2bc20d52324f5c3 100644
--- a/chrome/common/extensions/api/idltest.idl
+++ b/chrome/common/extensions/api/idltest.idl
@@ -17,8 +17,9 @@ namespace idltest {
     // 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