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

net/spdy/spdy_protocol.cc

Index: net/spdy/spdy_protocol.cc
diff --git a/net/spdy/spdy_protocol.cc b/net/spdy/spdy_protocol.cc
index 3dbbfde9e6df3e77612055c95ff7964e6b94a836..e8dd952fcbca8075e5354f734db086788f71728f 100644
--- a/net/spdy/spdy_protocol.cc
+++ b/net/spdy/spdy_protocol.cc
@@ -750,7 +750,11 @@ SpdyFrameWithHeaderBlockIR::SpdyFrameWithHeaderBlockIR(
 SpdyFrameWithHeaderBlockIR::~SpdyFrameWithHeaderBlockIR() {}
 
 SpdyDataIR::SpdyDataIR(SpdyStreamId stream_id, base::StringPiece data)
-    : SpdyFrameWithFinIR(stream_id), padded_(false), padding_payload_len_(0) {
+    : SpdyFrameWithFinIR(stream_id),
+      data_(nullptr),
+      data_len_(0),
+      padded_(false),
+      padding_payload_len_(0) {
   SetDataDeep(data);
 }
 
@@ -760,12 +764,17 @@ SpdyDataIR::SpdyDataIR(SpdyStreamId stream_id, const char* data)
 SpdyDataIR::SpdyDataIR(SpdyStreamId stream_id, std::string data)
     : SpdyFrameWithFinIR(stream_id),
       data_store_(base::MakeUnique<std::string>(std::move(data))),
-      data_(*data_store_),
+      data_(data_store_->data()),
+      data_len_(data_store_->size()),
       padded_(false),
       padding_payload_len_(0) {}
 
 SpdyDataIR::SpdyDataIR(SpdyStreamId stream_id)
-    : SpdyFrameWithFinIR(stream_id), padded_(false), padding_payload_len_(0) {}
+    : SpdyFrameWithFinIR(stream_id),
+      data_(nullptr),
+      data_len_(0),
+      padded_(false),
+      padding_payload_len_(0) {}
 
 SpdyDataIR::~SpdyDataIR() {}