[tracing] Switch to new heap dump format.

base/trace_event/memory_dump_session_state.cc

Index: base/trace_event/memory_dump_session_state.cc
diff --git a/base/trace_event/memory_dump_session_state.cc b/base/trace_event/memory_dump_session_state.cc
index d26b82a5b74c65f774403eb7fae1cc88ba556f7f..3b6cb0f4f57c4e411393f2b07e3d79a2043a930d 100644
--- a/base/trace_event/memory_dump_session_state.cc
+++ b/base/trace_event/memory_dump_session_state.cc
@@ -4,6 +4,11 @@
 
 #include "base/trace_event/memory_dump_session_state.h"
 
+#include "base/memory/ptr_util.h"
+#include "base/trace_event/heap_profiler_stack_frame_deduplicator.h"
+#include "base/trace_event/heap_profiler_string_deduplicator.h"
+#include "base/trace_event/heap_profiler_type_name_deduplicator.h"
+
 namespace base {
 namespace trace_event {
 
@@ -11,16 +16,12 @@ MemoryDumpSessionState::MemoryDumpSessionState()
     : heap_profiler_breakdown_threshold_bytes_(0) {}
 MemoryDumpSessionState::~MemoryDumpSessionState() {}
 
-void MemoryDumpSessionState::SetStackFrameDeduplicator(
-    std::unique_ptr<StackFrameDeduplicator> stack_frame_deduplicator) {
-  DCHECK(!stack_frame_deduplicator_);
-  stack_frame_deduplicator_ = std::move(stack_frame_deduplicator);
-}
-
-void MemoryDumpSessionState::SetTypeNameDeduplicator(
-    std::unique_ptr<TypeNameDeduplicator> type_name_deduplicator) {
-  DCHECK(!type_name_deduplicator_);
-  type_name_deduplicator_ = std::move(type_name_deduplicator);
+void MemoryDumpSessionState::CreateDeduplicators() {
+  string_deduplicator_ = base::MakeUnique<StringDeduplicator>();
+  stack_frame_deduplicator_ =
+      base::MakeUnique<StackFrameDeduplicator>(string_deduplicator_.get());
+  type_name_deduplicator_ =
+      base::MakeUnique<TypeNameDeduplicator>(string_deduplicator_.get());
 }
 
 void MemoryDumpSessionState::SetAllowedDumpModes(