memory coordinator: Use free memory to guess available memory on Linux

content/browser/memory/memory_monitor_linux_unittest.cc

 // Copyright (c) 2016 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 "content/browser/memory/memory_monitor_linux.h"
 
 #include "content/browser/memory/test_memory_monitor.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
@@ skipping 46 matching lines @@
 
   monitor_.reset(new MemoryMonitorLinux(&delegate_));
   EXPECT_EQ(0u, delegate_.calls());
 
   delegate_.SetAvailableMemoryKB(200 * kKBperMB);
   EXPECT_EQ(200, monitor_->GetFreeMemoryUntilCriticalMB());
   EXPECT_EQ(1U, delegate_.calls());
   delegate_.ResetCalls();
 
   delegate_.SetFreeMemoryKB(64 * kKBperMB, 32 * kKBperMB, 16 * kKBperMB);
-  EXPECT_EQ(112, monitor_->GetFreeMemoryUntilCriticalMB());
+  EXPECT_EQ(64, monitor_->GetFreeMemoryUntilCriticalMB());
   EXPECT_EQ(1U, delegate_.calls());
   delegate_.ResetCalls();
 
   delegate_.SetFreeMemoryKB(0, 0, 0);
   EXPECT_EQ(0, monitor_->GetFreeMemoryUntilCriticalMB());
   EXPECT_EQ(1U, delegate_.calls());
   delegate_.ResetCalls();
 }
 
 }  // namespace content