Advertise a minimum alignment for SharedMemory::Map().

base/shared_memory_win.cc

 // Copyright (c) 2011 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/shared_memory.h"
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 
 namespace base {
@@ skipping 118 matching lines @@
   return false;
 }
 
 bool SharedMemory::Map(uint32 bytes) {
   if (mapped_file_ == NULL)
     return false;
 
   memory_ = MapViewOfFile(mapped_file_,
       read_only_ ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS, 0, 0, bytes);
   if (memory_ != NULL) {
+    DCHECK_EQ(0U, reinterpret_cast<uintptr_t>(memory_) &
+        (SharedMemory::kMapMinimumAlignment - 1));
     return true;
   }
   return false;
 }
 
 bool SharedMemory::Unmap() {
   if (memory_ == NULL)
     return false;
 
   UnmapViewOfFile(memory_);
@@ skipping 66 matching lines @@
 void SharedMemory::Unlock() {
   DCHECK(lock_ != NULL);
   ReleaseMutex(lock_);
 }
 
 SharedMemoryHandle SharedMemory::handle() const {
   return mapped_file_;
 }
 
 }  // namespace base