Eliminate use of StringPiece(nullptr, n) with non zero n.

net/spdy/spdy_protocol_test_utils.cc

Index: net/spdy/spdy_protocol_test_utils.cc
diff --git a/net/spdy/spdy_protocol_test_utils.cc b/net/spdy/spdy_protocol_test_utils.cc
index baa718af0d981ceadadeb1aa48ff425d244964fb..dd600ded2d5a227372b8699cb496f793b42bd87b 100644
--- a/net/spdy/spdy_protocol_test_utils.cc
+++ b/net/spdy/spdy_protocol_test_utils.cc
@@ -48,9 +48,12 @@ namespace test {
     return ::testing::AssertionFailure();
   if (expected.fin() != actual.fin())
     return ::testing::AssertionFailure();
-  if (expected.data().size() != actual.data().size())
+  if (expected.data_len() != actual.data_len())
     return ::testing::AssertionFailure();
-  if (expected.data() != actual.data())
+  if (expected.data() == nullptr && actual.data() != nullptr)
+    return ::testing::AssertionFailure();
+  if (base::StringPiece(expected.data(), expected.data_len()) !=
+      base::StringPiece(actual.data(), actual.data_len()))
     return ::testing::AssertionFailure();
   if (!VerifySpdyFrameWithPaddingIREquals(expected, actual))
     return ::testing::AssertionFailure();