Revert 268371 "base: Increase emulated discardable memory limit."

base/memory/discardable_memory_emulated.cc

 // Copyright 2013 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_memory_emulated.h"
 
 #include "base/lazy_instance.h"
 #include "base/memory/discardable_memory_manager.h"
 
 namespace base {
 namespace {
 
-// This is admittedly pretty magical. It's approximately enough memory for eight
+// This is admittedly pretty magical. It's approximately enough memory for four
 // 2560x1600 images.
-const size_t kEmulatedMemoryLimit = 128 * 1024 * 1024;
-const size_t kEmulatedBytesToKeepUnderModeratePressure = 12 * 1024 * 1024;
+const size_t kEmulatedMemoryLimit = 64 * 1024 * 1024;
+const size_t kEmulatedBytesToKeepUnderModeratePressure =
+    kEmulatedMemoryLimit / 4;
 
 struct SharedState {
   SharedState()
       : manager(kEmulatedMemoryLimit,
                 kEmulatedBytesToKeepUnderModeratePressure) {}
 
   internal::DiscardableMemoryManager manager;
 };
 LazyInstance<SharedState>::Leaky g_shared_state = LAZY_INSTANCE_INITIALIZER;
 
@@ skipping 63 matching lines @@
   memory_.reset(new uint8[bytes_]);
   return false;
 }
 
 void DiscardableMemoryEmulated::Purge() {
   memory_.reset();
 }
 
 }  // namespace internal
 }  // namespace base