Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/spdy_write_queue_unittest.cc

Index: net/spdy/spdy_write_queue_unittest.cc
diff --git a/net/spdy/spdy_write_queue_unittest.cc b/net/spdy/spdy_write_queue_unittest.cc
index c3587ace5692f7eb7ac60eacff749cc25e756181..7318be2971b738f5e81bf02b8d7334ff953e074e 100644
--- a/net/spdy/spdy_write_queue_unittest.cc
+++ b/net/spdy/spdy_write_queue_unittest.cc
@@ -10,6 +10,7 @@
 #include <string>
 #include <utility>
 
+#include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/base/request_priority.h"
@@ -61,6 +62,11 @@ class RequeingBufferProducer : public SpdyBufferProducer {
     return std::move(buffer_);
   }
 
+  size_t EstimateMemoryUsage() const override {
+    NOTREACHED();
+    return 0;
+  }
+
   static void ConsumeCallback(SpdyWriteQueue* queue,
                               size_t size,
                               SpdyBuffer::ConsumeSource source) {