Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/spdy_protocol.h

Index: net/spdy/spdy_protocol.h
diff --git a/net/spdy/spdy_protocol.h b/net/spdy/spdy_protocol.h
index 9d4ec44fc52c97015417132af5cf820bafc380be..f395a75d96dade970b3a5db3d5682b76486028f1 100644
--- a/net/spdy/spdy_protocol.h
+++ b/net/spdy/spdy_protocol.h
@@ -858,6 +858,13 @@ class SpdySerializedFrame {
     return buffer;
   }
 
+  // Returns the estimate of dynamically allocated memory in bytes.
+  size_t EstimateMemoryUsage() const {
+    if (owns_buffer_)
+      return size_;
+    return 0;
+  }
+
  protected:
   char* frame_;