Introduce SmallTypedArray IDL type and use it for bufferSubData

Source/bindings/scripts/v8_types.py

Index: Source/bindings/scripts/v8_types.py
diff --git a/Source/bindings/scripts/v8_types.py b/Source/bindings/scripts/v8_types.py
index dcce52845ade81fd27a782f71c4a7199b08ca247..948d16b470be5339de0ddf3e6ec79b466c94c540 100644
--- a/Source/bindings/scripts/v8_types.py
+++ b/Source/bindings/scripts/v8_types.py
@@ -54,6 +54,7 @@ NON_WRAPPER_TYPES = frozenset([
     'EventListener',
     'NodeFilter',
     'SerializedScriptValue',
+    'SmallTypedArray',
 ])
 TYPED_ARRAY_TYPES = frozenset([
     'Float32Array',
@@ -111,6 +112,7 @@ CPP_SPECIAL_CONVERSION_RULES = {
     'NodeFilter': 'RefPtrWillBeRawPtr<NodeFilter>',
     'Promise': 'ScriptPromise',
     'ScriptValue': 'ScriptValue',
+    'SmallTypedArray': 'std::pair<void*, size_t>',
     # FIXME: Eliminate custom bindings for XPathNSResolver  http://crbug.com/345529
     'XPathNSResolver': 'RefPtrWillBeRawPtr<XPathNSResolver>',
     'boolean': 'bool',
@@ -492,6 +494,7 @@ V8_VALUE_TO_CPP_VALUE = {
     'Promise': 'ScriptPromise::cast(ScriptState::current({isolate}), {v8_value})',
     'SerializedScriptValue': 'SerializedScriptValueFactory::instance().create({v8_value}, 0, 0, exceptionState, {isolate})',
     'ScriptValue': 'ScriptValue(ScriptState::current({isolate}), {v8_value})',
+    'SmallTypedArray': '{v8_value}->IsArrayBufferView() ? {variable_name} = std::make_pair(alloca(v8::ArrayBufferView::Cast(*{v8_value})->ByteLength()), v8::ArrayBufferView::Cast(*{v8_value})->ByteLength()), v8::ArrayBufferView::Cast(*{v8_value})->CopyContents({variable_name}.first, {variable_name}.second), {variable_name} : std::make_pair(nullptr, 0)',

[Ken Russell (switch to Gerrit), 2015/04/14 01:40:26]

Is there any way to split this up into multiple expressions to make it more
readable and maintainable?

[Jens Widell, 2015/04/14 09:18:18]

I think we should make a helper function out of it, if we end up with this
approach. We have such helpers (V8XXX::toImpl() typically) for most object
types.

     'Window': 'toDOMWindow({isolate}, {v8_value})',
     'XPathNSResolver': 'toXPathNSResolver({isolate}, {v8_value})',
 }
@@ -514,6 +517,7 @@ TRIVIAL_CONVERSIONS = frozenset([
     'Date',
     'Dictionary',
     'NodeFilter',
+    'SmallTypedArray',
     'XPathNSResolver',
     'Promise'
 ])