Align base::Pickle allocations to 4k boundaries

base/memory/discardable_shared_memory.cc

 // Copyright 2014 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/memory/discardable_shared_memory.h"
 
 #if defined(OS_POSIX)
 #include <unistd.h>
 #endif
 
 #include <algorithm>
 
 #include "base/atomicops.h"
+#include "base/bits.h"
 #include "base/logging.h"
 #include "base/numerics/safe_math.h"
 #include "base/process/process_metrics.h"
 
 #if defined(OS_ANDROID)
 #include "third_party/ashmem/ashmem.h"
 #endif
 
 namespace base {
 namespace {
@@ skipping 58 matching lines @@
     UAtomicType u;
   } value;
 };
 
 // Shared state is stored at offset 0 in shared memory segments.
 SharedState* SharedStateFromSharedMemory(const SharedMemory& shared_memory) {
   DCHECK(shared_memory.memory());
   return static_cast<SharedState*>(shared_memory.memory());
 }
 
-// Round up |size| to a multiple of alignment, which must be a power of two.
-size_t Align(size_t alignment, size_t size) {
-  DCHECK_EQ(alignment & (alignment - 1), 0u);
-  return (size + alignment - 1) & ~(alignment - 1);
-}
-
 // Round up |size| to a multiple of page size.
 size_t AlignToPageSize(size_t size) {
-  return Align(base::GetPageSize(), size);
+  return bits::Align(size, base::GetPageSize());
 }
 
 }  // namespace
 
 DiscardableSharedMemory::DiscardableSharedMemory()
     : mapped_size_(0), locked_page_count_(0) {
 }
 
 DiscardableSharedMemory::DiscardableSharedMemory(
     SharedMemoryHandle shared_memory_handle)
@@ skipping 256 matching lines @@
   NOTIMPLEMENTED();
 #endif
 }
 #endif
 
 Time DiscardableSharedMemory::Now() const {
   return Time::Now();
 }
 
 }  // namespace base