Update from https://crrev.com/333737

base/trace_event/memory_allocator_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/memory_allocator_dump.h"
 
 #include "base/format_macros.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/memory_dump_provider.h"
@@ skipping 14 matching lines @@
   const StringValue* str_value = nullptr;
   if (!dict_value->GetWithoutPathExpansion(key, &value))
     return false;
   if (!value->GetAsString(&str_value))
     return false;
   *out_cstr = str_value->GetString().c_str();
   return true;
 }
 }  // namespace
 
+// TODO(primiano): remove kName{Inner,Outer}Size below after all the existing
+// dump providers have been rewritten.
+const char MemoryAllocatorDump::kNameSize[] = "size";
+const char MemoryAllocatorDump::kNameInnerSize[] = "inner_size";
 const char MemoryAllocatorDump::kNameOuterSize[] = "outer_size";
-const char MemoryAllocatorDump::kNameInnerSize[] = "inner_size";
 const char MemoryAllocatorDump::kNameObjectsCount[] = "objects_count";
 const char MemoryAllocatorDump::kTypeScalar[] = "scalar";
 const char MemoryAllocatorDump::kTypeString[] = "string";
 const char MemoryAllocatorDump::kUnitsBytes[] = "bytes";
 const char MemoryAllocatorDump::kUnitsObjects[] = "objects";
 
 MemoryAllocatorDump::MemoryAllocatorDump(const std::string& absolute_name,
-                                         ProcessMemoryDump* process_memory_dump)
-    : absolute_name_(absolute_name), process_memory_dump_(process_memory_dump) {
+                                         ProcessMemoryDump* process_memory_dump,
+                                         const MemoryAllocatorDumpGuid& guid)
+    : absolute_name_(absolute_name),
+      process_memory_dump_(process_memory_dump),
+      guid_(guid) {
   // The |absolute_name| cannot be empty.
   DCHECK(!absolute_name.empty());
 
   // The |absolute_name| can contain slash separator, but not leading or
   // trailing ones.
   DCHECK(absolute_name[0] != '/' && *absolute_name.rbegin() != '/');
 
   // Dots are not allowed anywhere as the underlying base::DictionaryValue
   // would treat them magically and split in sub-nodes, which is not intended.
   DCHECK_EQ(std::string::npos, absolute_name.find_first_of('.'));
 }
 
+// If the caller didn't provide a guid, make one up by hashing the
+// absolute_name with the current PID.
+// Rationale: |absolute_name| is already supposed to be unique within a
+// process, the pid will make it unique among all processes.
+MemoryAllocatorDump::MemoryAllocatorDump(const std::string& absolute_name,
+                                         ProcessMemoryDump* process_memory_dump)
+    : MemoryAllocatorDump(absolute_name,
+                          process_memory_dump,
+                          MemoryAllocatorDumpGuid(StringPrintf(
+                              "%d:%s",
+                              TraceLog::GetInstance()->process_id(),
+                              absolute_name.c_str()))) {
+}
+
 MemoryAllocatorDump::~MemoryAllocatorDump() {
 }
 
 void MemoryAllocatorDump::Add(const std::string& name,
                               const char* type,
                               const char* units,
                               scoped_ptr<Value> value) {
   scoped_ptr<DictionaryValue> attribute(new DictionaryValue());
   DCHECK(!attributes_.HasKey(name));
   attribute->SetStringWithoutPathExpansion("type", type);
@@ skipping 22 matching lines @@
   return true;
 }
 
 void MemoryAllocatorDump::AddScalar(const std::string& name,
                                     const char* units,
                                     uint64 value) {
   scoped_ptr<Value> hex_value(new StringValue(StringPrintf("%" PRIx64, value)));
   Add(name, kTypeScalar, units, hex_value.Pass());
 }
 
+void MemoryAllocatorDump::AddScalarF(const std::string& name,
+                                     const char* units,
+                                     double value) {
+  Add(name, kTypeScalar, units, make_scoped_ptr(new FundamentalValue(value)));
+}
+
 void MemoryAllocatorDump::AddString(const std::string& name,
                                     const char* units,
                                     const std::string& value) {
   scoped_ptr<Value> str_value(new StringValue(value));
   Add(name, kTypeString, units, str_value.Pass());
 }
 
 void MemoryAllocatorDump::AsValueInto(TracedValue* value) const {
   value->BeginDictionary(absolute_name_.c_str());
+  value->SetString("guid", guid_.ToString());
+
   value->BeginDictionary("attrs");
 
   for (DictionaryValue::Iterator it(attributes_); !it.IsAtEnd(); it.Advance())
     value->SetValue(it.key().c_str(), it.value().CreateDeepCopy());
 
   value->EndDictionary();  // "attrs": { ... }
   value->EndDictionary();  // "allocator_name/heap_subheap": { ... }
 }
 
 }  // namespace trace_event
 }  // namespace base