binding: Removes unused code in templates/attributes.cpp.

Faking {{cpp_class}} and {{c8_class}} doesn't make sense.
Probably it made sense before the introduction of virtual
ScriptWrappable::wrap().

Checking the existence of window->document() doesn't seem
making sense to me, and CQ tests seem passing without the
check.

BUG=

Review-Url: https://codereview.chromium.org/2268433002
Cr-Commit-Position: refs/heads/master@{#413375}
static void perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArgMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
{
    ExceptionState exceptionState(ExceptionState::ExecutionContext, "perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArg", "TestInterfaceNode", info.Holder(), info.GetIsolate());
    TestInterfaceNode* impl = V8TestInterfaceNode::toImpl(info.Holder());
    bool optionalBooleanArgument;
    {
        int numArgsPassed = info.Length();
        while (numArgsPassed > 0) {
            if (!info[numArgsPassed - 1]->IsUndefined())
                break;
            --numArgsPassed;
        }
        if (UNLIKELY(numArgsPassed <= 0)) {
            v8SetReturnValueFast(info, impl->perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArg(), impl);
            return;
        }
        optionalBooleanArgument = toBoolean(info.GetIsolate(), info[0], exceptionState);
        if (exceptionState.throwIfNeeded())
            return;
    }
    v8SetReturnValueFast(info, impl->perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArg(optionalBooleanArgument), impl);
}

static void perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArgMethod(const v8::FunctionCallbackInfo<v8::Value>& info)
{
    ExceptionState exceptionState(ExceptionState::ExecutionContext, "perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArg", "TestInterfaceNode", info.Holder(), info.GetIsolate());
    TestInterfaceNode* impl = V8TestInterfaceNode::toImpl(info.Holder());
    bool optionalBooleanArgument;
    {
        int numArgsPassed = info.Length();
        while (numArgsPassed > 0) {
            if (!info[numArgsPassed - 1]->IsUndefined())
                break;
            --numArgsPassed;
        }
        if (UNLIKELY(numArgsPassed <= 0)) {
            v8SetReturnValueFast(info, impl->perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArg(), impl);
            return;
        }
        optionalBooleanArgument = toBoolean(info.GetIsolate(), info[0], exceptionState);
        if (exceptionState.throwIfNeeded())
            return;
    }
    v8SetReturnValueFast(info, impl->perWorldBindingsTestInterfaceEmptyMethodOptionalBooleanArg(optionalBooleanArgument), impl);
}
