Revert "Revert 239763 "Add DiscardableMemoryAllocator to minimize use of...""

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..c9f67b2556f17a24a1e7f65d9533403106e6c94e 100644
--- a/base/memory/discardable_memory_unittest.cc
+++ b/base/memory/discardable_memory_unittest.cc
@@ -3,12 +3,29 @@
 // found in the LICENSE file.
 
 #include "base/memory/discardable_memory.h"
+
+#include <limits>
+
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 const size_t kSize = 1024;
 
+#if defined(OS_ANDROID)
+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);
+}
+#endif
+
 TEST(DiscardableMemoryTest, SupportedNatively) {
 #if defined(DISCARDABLE_MEMORY_ALWAYS_SUPPORTED_NATIVELY)
   ASSERT_TRUE(DiscardableMemory::SupportedNatively());