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

BUG=371897
R=rockot@chromium.org
TEST=ran UsbApiTest.TransferEvent under Dr. Memory

Review URL: https://codereview.chromium.org/275993002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@269620 0039d316-1c4b-4281-b951-d872f2087c98

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