Add DiscardableMemoryAllocator to work around FD limit issue.

base/memory/discardable_memory_unittest.cc

Index: base/memory/discardable_memory_unittest.cc
diff --git a/base/memory/discardable_memory_unittest.cc b/base/memory/discardable_memory_unittest.cc
index eb730f19f18e8482fde972598c99378f2c30447a..c900551535d9581348788825ac8d8563ffb7eeaa 100644
--- a/base/memory/discardable_memory_unittest.cc
+++ b/base/memory/discardable_memory_unittest.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <limits>
+
 #include "base/memory/discardable_memory.h"

[willchan no longer on Chromium, 2013/12/01 00:58:56]

foo.h always goes first in foo_unittest.cc, see the example in the style guide
for basictypes_unittest.cc and basictypes.h.

[Philippe, 2013/12/02 10:56:39]

Done.

 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -9,6 +11,18 @@ namespace base {
 
 const size_t kSize = 1024;
 
+TEST(DiscardableMemoryTest, TooLargeAllocationFails) {
+  const size_t kPageSize = 4096;
+  const size_t max_allowed_allocation_size =
+      std::numeric_limits<size_t>::max() - kPageSize + 1;
+  scoped_ptr<DiscardableMemory> memory(
+      DiscardableMemory::CreateLockedMemory(max_allowed_allocation_size + 1));
+  // On certain platforms (e.g. Android), page-alignment would have caused an
+  // overflow resulting in a small allocation if the input size wasn't checked
+  // correctly.
+  ASSERT_FALSE(memory);
+}
+
 TEST(DiscardableMemoryTest, SupportedNatively) {
 #if defined(DISCARDABLE_MEMORY_ALWAYS_SUPPORTED_NATIVELY)
   ASSERT_TRUE(DiscardableMemory::SupportedNatively());