Fix base:: namespace for Lock.

tools/memory_watcher/memory_hook.cc

 // Copyright (c) 2006-2008 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.
 
 // Static class for hooking Win32 API routines.
 
 // Some notes about how to hook Memory Allocation Routines in Windows.
 //
 // For our purposes we do not hook the libc routines.  There are two
 // reasons for this.  First, the libc routines all go through HeapAlloc
@@ skipping 257 matching lines @@
     chunk_size = info.RegionSize;
   bool decommit = (info.State & MEM_COMMIT);
 
   if (decommit)
       MemoryHook::hook()->OnUntrack(0, reinterpret_cast<int32>(address),
                                      chunk_size);
 
   return patch_VirtualFreeEx()(process, address, size, type);
 }
 
-static Lock known_maps_lock;
+static base::Lock known_maps_lock;
 static std::map<void*, int> known_maps;
 
 static LPVOID WINAPI Perftools_MapViewOfFileEx(HANDLE hFileMappingObject,
                                                DWORD dwDesiredAccess,
                                                DWORD dwFileOffsetHigh,
                                                DWORD dwFileOffsetLow,
                                                SIZE_T dwNumberOfBytesToMap,
                                                LPVOID lpBaseAddress) {
   // For this function pair, you always deallocate the full block of
   // data that you allocate, so NewHook/DeleteHook is the right API.
@@ skipping 264 matching lines @@
 }
 
 void MemoryHook::OnUntrack(HANDLE heap, int32 id, int32 size) {
   // Don't notify about allocations to our internal heap.
   if (heap == heap_)
     return;
 
   if (watcher_)
     watcher_->OnUntrack(heap, id, size);
 }