Update from https://crrev.com/333737

base/trace_event/process_memory_dump.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/trace_event/process_memory_dump.h"
 
 #include "base/trace_event/process_memory_totals.h"
 #include "base/trace_event/trace_event_argument.h"
 
 namespace base {
 namespace trace_event {
 
+namespace {
+const char kEdgeTypeOwnership[] = "ownership";
+
+std::string GetSharedGlobalAllocatorDumpName(
+    const MemoryAllocatorDumpGuid& guid) {
+  return "global/" + guid.ToString();
+}
+}  // namespace
+
 ProcessMemoryDump::ProcessMemoryDump(
     const scoped_refptr<MemoryDumpSessionState>& session_state)
     : has_process_totals_(false),
       has_process_mmaps_(false),
       session_state_(session_state) {
 }
 
 ProcessMemoryDump::~ProcessMemoryDump() {
 }
 
 MemoryAllocatorDump* ProcessMemoryDump::CreateAllocatorDump(
     const std::string& absolute_name) {
   MemoryAllocatorDump* mad = new MemoryAllocatorDump(absolute_name, this);
-  DCHECK_EQ(0ul, allocator_dumps_.count(absolute_name));
+  AddAllocatorDumpInternal(mad);  // Takes ownership of |mad|.
+  return mad;
+}
+
+MemoryAllocatorDump* ProcessMemoryDump::CreateAllocatorDump(
+    const std::string& absolute_name,
+    const MemoryAllocatorDumpGuid& guid) {
+  MemoryAllocatorDump* mad = new MemoryAllocatorDump(absolute_name, this, guid);
+  AddAllocatorDumpInternal(mad);  // Takes ownership of |mad|.
+  return mad;
+}
+
+void ProcessMemoryDump::AddAllocatorDumpInternal(MemoryAllocatorDump* mad) {
+  DCHECK_EQ(0ul, allocator_dumps_.count(mad->absolute_name()));
   allocator_dumps_storage_.push_back(mad);
-  allocator_dumps_[absolute_name] = mad;
-  return mad;
+  allocator_dumps_[mad->absolute_name()] = mad;
 }
 
 MemoryAllocatorDump* ProcessMemoryDump::GetAllocatorDump(
     const std::string& absolute_name) const {
   auto it = allocator_dumps_.find(absolute_name);
   return it == allocator_dumps_.end() ? nullptr : it->second;
 }
 
+MemoryAllocatorDump* ProcessMemoryDump::CreateSharedGlobalAllocatorDump(
+    const MemoryAllocatorDumpGuid& guid) {
+  return CreateAllocatorDump(GetSharedGlobalAllocatorDumpName(guid), guid);
+}
+
+MemoryAllocatorDump* ProcessMemoryDump::GetSharedGlobalAllocatorDump(
+    const MemoryAllocatorDumpGuid& guid) const {
+  return GetAllocatorDump(GetSharedGlobalAllocatorDumpName(guid));
+}
+
+void ProcessMemoryDump::Clear() {
+  if (has_process_totals_) {
+    process_totals_.Clear();
+    has_process_totals_ = false;
+  }
+
+  if (has_process_mmaps_) {
+    process_mmaps_.Clear();
+    has_process_mmaps_ = false;
+  }
+
+  allocator_dumps_storage_.clear();
+  allocator_dumps_.clear();
+  allocator_dumps_edges_.clear();
+}
+
+void ProcessMemoryDump::TakeAllDumpsFrom(ProcessMemoryDump* other) {
+  DCHECK(!other->has_process_totals() && !other->has_process_mmaps());
+
+  // Moves the ownership of all MemoryAllocatorDump(s) contained in |other|
+  // into this ProcessMemoryDump.
+  for (MemoryAllocatorDump* mad : other->allocator_dumps_storage_) {
+    // Check that we don't merge duplicates.
+    DCHECK_EQ(0ul, allocator_dumps_.count(mad->absolute_name()));
+    allocator_dumps_storage_.push_back(mad);
+    allocator_dumps_[mad->absolute_name()] = mad;
+  }
+  other->allocator_dumps_storage_.weak_clear();
+  other->allocator_dumps_.clear();
+
+  // Move all the edges.
+  allocator_dumps_edges_.insert(allocator_dumps_edges_.end(),
+                                other->allocator_dumps_edges_.begin(),
+                                other->allocator_dumps_edges_.end());
+  other->allocator_dumps_edges_.clear();
+}
+
 void ProcessMemoryDump::AsValueInto(TracedValue* value) const {
-  // Build up the [dumper name] -> [value] dictionary.
   if (has_process_totals_) {
     value->BeginDictionary("process_totals");
     process_totals_.AsValueInto(value);
     value->EndDictionary();
   }
+
   if (has_process_mmaps_) {
     value->BeginDictionary("process_mmaps");
     process_mmaps_.AsValueInto(value);
     value->EndDictionary();
   }
+
   if (allocator_dumps_storage_.size() > 0) {
     value->BeginDictionary("allocators");
     for (const MemoryAllocatorDump* allocator_dump : allocator_dumps_storage_)
       allocator_dump->AsValueInto(value);
     value->EndDictionary();
   }
+
+  value->BeginArray("allocators_graph");
+  for (const MemoryAllocatorDumpEdge& edge : allocator_dumps_edges_) {
+    value->BeginDictionary();
+    value->SetString("source", edge.source.ToString());
+    value->SetString("target", edge.target.ToString());
+    value->SetInteger("importance", edge.importance);
+    value->SetString("type", edge.type);
+    value->EndDictionary();
+  }
+  value->EndArray();
+}
+
+void ProcessMemoryDump::AddOwnershipEdge(const MemoryAllocatorDumpGuid& source,
+                                         const MemoryAllocatorDumpGuid& target,
+                                         int importance) {
+  allocator_dumps_edges_.push_back(
+      {source, target, importance, kEdgeTypeOwnership});
+}
+
+void ProcessMemoryDump::AddOwnershipEdge(
+    const MemoryAllocatorDumpGuid& source,
+    const MemoryAllocatorDumpGuid& target) {
+  AddOwnershipEdge(source, target, 0 /* importance */);
+}
+
+void ProcessMemoryDump::AddSuballocation(const MemoryAllocatorDumpGuid& source,
+                                         const std::string& target_node_name) {
+  std::string child_mad_name = target_node_name + "/__" + source.ToString();
+  MemoryAllocatorDump* target_child_mad = CreateAllocatorDump(child_mad_name);
+  AddOwnershipEdge(source, target_child_mad->guid());
 }
 
 }  // namespace trace_event
 }  // namespace base