Added memory pressure monitor for linux.

base/memory/memory_pressure_monitor_mac_unittest.cc

Index: base/memory/memory_pressure_monitor_mac_unittest.cc
diff --git a/base/memory/memory_pressure_monitor_mac_unittest.cc b/base/memory/memory_pressure_monitor_mac_unittest.cc
index e037a9dcdd6d65df9e907303c84acce421bca2b8..cdf986bd7e0e3b3f01f6d12c97d5e77a68830378 100644
--- a/base/memory/memory_pressure_monitor_mac_unittest.cc
+++ b/base/memory/memory_pressure_monitor_mac_unittest.cc
@@ -2,12 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/memory/memory_pressure_monitor_mac.h"
+#include "base/memory/memory_pressure_monitor.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
-namespace mac {
 
 class TestMemoryPressureMonitor : public MemoryPressureMonitor {
  public:
@@ -58,5 +57,4 @@ TEST(MacMemoryPressureMonitorTest, CurrentMemoryPressure) {
                   MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL);
 }
 
-}  // namespace mac
 }  // namespace base