Instrument SourceStream using MemoryDumpProvider

net/filter/brotli_source_stream.cc

Index: net/filter/brotli_source_stream.cc
diff --git a/net/filter/brotli_source_stream.cc b/net/filter/brotli_source_stream.cc
index 2ad18c39f156fff5aa56b6fb85767c7673869f97..8870b53259ac7b9b4ac14f7f9d23d161183c03d9 100644
--- a/net/filter/brotli_source_stream.cc
+++ b/net/filter/brotli_source_stream.cc
@@ -10,6 +10,9 @@
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/strings/stringprintf.h"
+#include "base/trace_event/memory_allocator_dump.h"
+#include "base/trace_event/process_memory_dump.h"
 #include "net/base/io_buffer.h"
 #include "third_party/brotli/include/brotli/decode.h"
 
@@ -75,6 +78,19 @@ class BrotliSourceStream : public FilterSourceStream {
                                 kBuckets);
   }
 
+  void DumpMemoryStatsImpl(
+      base::trace_event::ProcessMemoryDump* pmd,
+      const std::string& parent_dump_absolute_name) const override {
+    // Log pointer address to avoid duplication though in practice there is
+    // often only one BrotliSourceStream per URLRequest.
+    base::trace_event::MemoryAllocatorDump* brotli_dump =
+        pmd->CreateAllocatorDump(base::StringPrintf(
+            "%s/brotli_%p", parent_dump_absolute_name.c_str(), this));
+    brotli_dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                           base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                           used_memory_);
+  }
+
  private:
   // Reported in UMA and must be kept in sync with the histograms.xml file.
   enum class DecodingStatus : int {