[tracing] Switch to new heap dump format.

base/trace_event/memory_dump_manager.cc

Index: base/trace_event/memory_dump_manager.cc
diff --git a/base/trace_event/memory_dump_manager.cc b/base/trace_event/memory_dump_manager.cc
index 5a54a773c5e4eb8b7eb816000855e23dc0374780..ee2325eb5a42ba3cf9bf2cb089b77bce923831a9 100644
--- a/base/trace_event/memory_dump_manager.cc
+++ b/base/trace_event/memory_dump_manager.cc
@@ -22,8 +22,7 @@
 #include "base/trace_event/heap_profiler.h"
 #include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 #include "base/trace_event/heap_profiler_event_filter.h"
-#include "base/trace_event/heap_profiler_stack_frame_deduplicator.h"
-#include "base/trace_event/heap_profiler_type_name_deduplicator.h"
+#include "base/trace_event/heap_profiler_event_writer.h"
 #include "base/trace_event/malloc_dump_provider.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "base/trace_event/memory_dump_scheduler.h"
@@ -90,33 +89,6 @@ void OnGlobalDumpDone(MemoryDumpCallback wrapped_callback,
   }
 }
 
-// Proxy class which wraps a ConvertableToTraceFormat owned by the
-// |session_state| into a proxy object that can be added to the trace event log.
-// This is to solve the problem that the MemoryDumpSessionState is refcounted
-// but the tracing subsystem wants a std::unique_ptr<ConvertableToTraceFormat>.
-template <typename T>
-struct SessionStateConvertableProxy : public ConvertableToTraceFormat {
-  using GetterFunctPtr = T* (MemoryDumpSessionState::*)() const;
-
-  SessionStateConvertableProxy(
-      scoped_refptr<MemoryDumpSessionState> session_state,
-      GetterFunctPtr getter_function)
-      : session_state(session_state), getter_function(getter_function) {}
-
-  void AppendAsTraceFormat(std::string* out) const override {
-    return (session_state.get()->*getter_function)()->AppendAsTraceFormat(out);
-  }
-
-  void EstimateTraceMemoryOverhead(
-      TraceEventMemoryOverhead* overhead) override {
-    return (session_state.get()->*getter_function)()
-        ->EstimateTraceMemoryOverhead(overhead);
-  }
-
-  scoped_refptr<MemoryDumpSessionState> session_state;
-  GetterFunctPtr const getter_function;
-};
-
 }  // namespace
 
 // static
@@ -807,26 +779,11 @@ void MemoryDumpManager::OnTraceLogEnabled() {
   session_state->set_heap_profiler_breakdown_threshold_bytes(
       memory_dump_config.heap_profiler_options.breakdown_threshold_bytes);
   if (heap_profiling_enabled_) {
-    // If heap profiling is enabled, the stack frame deduplicator and type name
-    // deduplicator will be in use. Add a metadata events to write the frames
-    // and type IDs.
-    session_state->SetStackFrameDeduplicator(
-        WrapUnique(new StackFrameDeduplicator));
-
-    session_state->SetTypeNameDeduplicator(
-        WrapUnique(new TypeNameDeduplicator));
-
-    TRACE_EVENT_API_ADD_METADATA_EVENT(
-        TraceLog::GetCategoryGroupEnabled("__metadata"), "stackFrames",
-        "stackFrames",
-        MakeUnique<SessionStateConvertableProxy<StackFrameDeduplicator>>(
-            session_state, &MemoryDumpSessionState::stack_frame_deduplicator));
-
-    TRACE_EVENT_API_ADD_METADATA_EVENT(
-        TraceLog::GetCategoryGroupEnabled("__metadata"), "typeNames",
-        "typeNames",
-        MakeUnique<SessionStateConvertableProxy<TypeNameDeduplicator>>(
-            session_state, &MemoryDumpSessionState::type_name_deduplicator));
+    // TODO(dskiba): support continuous mode (crbug.com/701052)
+    LOG_IF(ERROR, trace_config.GetTraceRecordMode() != RECORD_CONTINUOUSLY)
+        << "Heap profile format is incremental and doesn't yet support "
+        << "continuous mode.";
+    session_state->CreateDeduplicators();
   }
 
   std::unique_ptr<MemoryDumpScheduler> dump_scheduler(