Align ashmem region sizes to page size after ashmem creation failed.

base/memory/discardable_memory_android.cc

Index: base/memory/discardable_memory_android.cc
diff --git a/base/memory/discardable_memory_android.cc b/base/memory/discardable_memory_android.cc
index 6f531447f6d2b71a628967a8de6b3bcb7c2ffce0..2004a360b0c980be7068012500b53ee98ec137a6 100644
--- a/base/memory/discardable_memory_android.cc
+++ b/base/memory/discardable_memory_android.cc
@@ -37,8 +37,7 @@ struct DiscardableMemoryAllocatorWrapper {
   static size_t GetOptimalAshmemRegionSizeForAllocator() {
     // Note that this may do some I/O (without hitting the disk though) so it
     // should not be called on the critical path.
-    return internal::AlignToNextPage(
-        base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8);
+    return base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8;
   }
 };
 
@@ -49,15 +48,6 @@ LazyInstance<DiscardableMemoryAllocatorWrapper>::Leaky g_context =
 
 namespace internal {
 
-size_t AlignToNextPage(size_t size) {
-  const size_t kPageSize = 4096;
-  DCHECK_EQ(static_cast<int>(kPageSize), getpagesize());
-  if (size > std::numeric_limits<size_t>::max() - kPageSize + 1)
-    return 0;
-  const size_t mask = ~(kPageSize - 1);
-  return (size + kPageSize - 1) & mask;
-}
-
 bool CreateAshmemRegion(const char* name,
                         size_t size,
                         int* out_fd,