Align base::Pickle allocations to 4k boundaries

base/bits_unittest.cc

 // Copyright (c) 2009 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.
 
 // This file contains the unit tests for the bit utilities.
 
 #include "base/bits.h"
+
+#include <limits>
+
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace bits {
 
 TEST(BitsTest, Log2Floor) {
   EXPECT_EQ(-1, Log2Floor(0));
   EXPECT_EQ(0, Log2Floor(1));
   EXPECT_EQ(1, Log2Floor(2));
   EXPECT_EQ(1, Log2Floor(3));
@@ skipping 19 matching lines @@
     unsigned int value = 1U << i;
     EXPECT_EQ(i, Log2Ceiling(value));
     EXPECT_EQ(i + 1, Log2Ceiling(value + 1));
     EXPECT_EQ(i + 1, Log2Ceiling(value + 2));
     EXPECT_EQ(i, Log2Ceiling(value - 1));
     EXPECT_EQ(i, Log2Ceiling(value - 2));
   }
   EXPECT_EQ(32, Log2Ceiling(0xffffffffU));
 }
 
+TEST(BitsTest, Align) {

[Lei Zhang, 2015/07/24 18:59:55]

Thanks!

+  const size_t kSizeTMax = std::numeric_limits<size_t>::max();
+  EXPECT_EQ(0ul, Align(0, 4));
+  EXPECT_EQ(4ul, Align(1, 4));
+  EXPECT_EQ(4096ul, Align(1, 4096));
+  EXPECT_EQ(4096ul, Align(4096, 4096));
+  EXPECT_EQ(4096ul, Align(4095, 4096));
+  EXPECT_EQ(8192ul, Align(4097, 4096));
+  EXPECT_EQ(kSizeTMax - 31, Align(kSizeTMax - 62, 32));
+  EXPECT_EQ(kSizeTMax / 2 + 1, Align(1, kSizeTMax / 2 + 1));
+}
+
 }  // namespace bits
 }  // namespace base