Initialize an IOBuffer in UsbApiTest.TransferEvent to avoid an uninitialized read.

extensions/browser/api/usb/usb_apitest.cc

Index: extensions/browser/api/usb/usb_apitest.cc
diff --git a/extensions/browser/api/usb/usb_apitest.cc b/extensions/browser/api/usb/usb_apitest.cc
index 335258de1349ac24735eb00d5f44c1c3cc73e2e6..b3770cef41230e5c8d362a3b4d2a7e1be58bc61f 100644
--- a/extensions/browser/api/usb/usb_apitest.cc
+++ b/extensions/browser/api/usb/usb_apitest.cc
@@ -27,7 +27,9 @@ namespace {
 ACTION_TEMPLATE(InvokeUsbTransferCallback,
                 HAS_1_TEMPLATE_PARAMS(int, k),
                 AND_1_VALUE_PARAMS(p1)) {
-  ::std::tr1::get<k>(args).Run(p1, new net::IOBuffer(1), 1);
+  net::IOBuffer* io_buffer = new net::IOBuffer(1);
+  memset(io_buffer->data(), 0, 1);  // Avoid uninitialized reads.
+  ::std::tr1::get<k>(args).Run(p1, io_buffer, 1);
 }
 
 // MSVC erroneously thinks that at least one of the arguments for the transfer