Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/spdy_framer_decoder_adapter.cc

Index: net/spdy/spdy_framer_decoder_adapter.cc
diff --git a/net/spdy/spdy_framer_decoder_adapter.cc b/net/spdy/spdy_framer_decoder_adapter.cc
index 634306983f370a09a4a96d148f2e3cdd79c09d8c..7886499da095b8121696a465bbd8b658f67c0a02 100644
--- a/net/spdy/spdy_framer_decoder_adapter.cc
+++ b/net/spdy/spdy_framer_decoder_adapter.cc
@@ -11,6 +11,7 @@
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
+#include "base/trace_event/memory_usage_estimator.h"
 
 #if defined(COMPILER_GCC)
 #define PRETTY_THIS base::StringPrintf("%s@%p ", __PRETTY_FUNCTION__, this)
@@ -231,6 +232,10 @@ class NestedSpdyFramerDecoder : public SpdyFramerDecoderAdapter {
   bool probable_http_response() const override {
     return framer_.probable_http_response();
   }
+  size_t EstimateMemoryUsage() const override {
+    // Skip |visitor_adapter_| because it doesn't allocate.
+    return base::trace_event::EstimateMemoryUsage(framer_);
+  }
 
  private:
   SpdyFramer framer_;