base: Add uncached malloc based discardable memory type.

base/memory/discardable_memory_linux.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.h"
 
 #include "base/logging.h"
 #include "base/memory/discardable_memory_emulated.h"
+#include "base/memory/discardable_memory_malloc.h"
 
 namespace base {
 
 // static
 void DiscardableMemory::RegisterMemoryPressureListeners() {
   internal::DiscardableMemoryEmulated::RegisterMemoryPressureListeners();
 }
 
 // static
 void DiscardableMemory::UnregisterMemoryPressureListeners() {
   internal::DiscardableMemoryEmulated::UnregisterMemoryPressureListeners();
 }
 
 // static
 void DiscardableMemory::GetSupportedTypes(
     std::vector<DiscardableMemoryType>* types) {
   const DiscardableMemoryType supported_types[] = {
-    DISCARDABLE_MEMORY_TYPE_EMULATED
+    DISCARDABLE_MEMORY_TYPE_EMULATED,
+    DISCARDABLE_MEMORY_TYPE_MALLOC
   };
   types->assign(supported_types, supported_types + arraysize(supported_types));
 }
 
 // static
 scoped_ptr<DiscardableMemory> DiscardableMemory::CreateLockedMemoryWithType(
     DiscardableMemoryType type, size_t size) {
   switch (type) {
     case DISCARDABLE_MEMORY_TYPE_NONE:
     case DISCARDABLE_MEMORY_TYPE_ANDROID:
     case DISCARDABLE_MEMORY_TYPE_MAC:
       return scoped_ptr<DiscardableMemory>();
     case DISCARDABLE_MEMORY_TYPE_EMULATED: {
       scoped_ptr<internal::DiscardableMemoryEmulated> memory(
           new internal::DiscardableMemoryEmulated(size));
       if (!memory->Initialize())
         return scoped_ptr<DiscardableMemory>();
 
       return memory.PassAs<DiscardableMemory>();
     }
+    case DISCARDABLE_MEMORY_TYPE_MALLOC: {
+      scoped_ptr<internal::DiscardableMemoryMalloc> memory(
+          new internal::DiscardableMemoryMalloc(size));
+      if (!memory->Initialize())
+        return scoped_ptr<DiscardableMemory>();
+
+      return memory.PassAs<DiscardableMemory>();
+    }
   }
 
   NOTREACHED();
   return scoped_ptr<DiscardableMemory>();
 }
 
 // static
 bool DiscardableMemory::PurgeForTestingSupported() {
   return true;
 }
 
 // static
 void DiscardableMemory::PurgeForTesting() {
   internal::DiscardableMemoryEmulated::PurgeForTesting();
 }
 
 }  // namespace base