Update to Chromium //base at Chromium commit 3e81715e6d3a4324362635aea46ce1f1a163cca1.

test/test_discardable_memory_allocator.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/test/test_discardable_memory_allocator.h"
 
 #include <stdint.h>
 
 #include "base/memory/discardable_memory.h"
 
 namespace base {
 namespace {
 
 class DiscardableMemoryImpl : public DiscardableMemory {
  public:
   explicit DiscardableMemoryImpl(size_t size) : data_(new uint8_t[size]) {}
 
   // Overridden from DiscardableMemory:
   bool Lock() override { return false; }
   void Unlock() override {}
   void* data() const override { return data_.get(); }
 
+  trace_event::MemoryAllocatorDump* CreateMemoryAllocatorDump(
+      const char* name,
+      trace_event::ProcessMemoryDump* pmd) const override {
+    return nullptr;
+  }
+
  private:
   scoped_ptr<uint8_t[]> data_;
 };
 
 }  // namespace
 
 TestDiscardableMemoryAllocator::TestDiscardableMemoryAllocator() {
 }
 
 TestDiscardableMemoryAllocator::~TestDiscardableMemoryAllocator() {
 }
 
 scoped_ptr<DiscardableMemory>
 TestDiscardableMemoryAllocator::AllocateLockedDiscardableMemory(size_t size) {
   return make_scoped_ptr(new DiscardableMemoryImpl(size));
 }
 
 }  // namespace base