Make memory pressure notifier configurable

base/memory/memory_pressure_monitor_chromeos.cc

 // Copyright 2014 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/memory_pressure_monitor_chromeos.h"
 
 #include <fcntl.h>
 #include <sys/select.h>
 
 #include "base/metrics/histogram_macros.h"
@@ skipping 95 matching lines @@
 MemoryPressureMonitor::MemoryPressureMonitor(
     MemoryPressureThresholds thresholds)
     : current_memory_pressure_level_(
           MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE),
       moderate_pressure_repeat_count_(0),
       moderate_pressure_threshold_percent_(
           GetModerateMemoryThresholdInPercent(thresholds)),
       critical_pressure_threshold_percent_(
           GetCriticalMemoryThresholdInPercent(thresholds)),
       low_mem_file_(HANDLE_EINTR(::open(kLowMemFile, O_RDONLY))),
+      dispatch_callback_(
+          base::Bind(&MemoryPressureListener::NotifyMemoryPressure)),
       weak_ptr_factory_(this) {
   StartObserving();
   LOG_IF(ERROR,
          base::SysInfo::IsRunningOnChromeOS() && !low_mem_file_.is_valid())
       << "Cannot open kernel listener";
 }
 
 MemoryPressureMonitor::~MemoryPressureMonitor() {
   StopObserving();
 }
@@ skipping 97 matching lines @@
   } else if (current_memory_pressure_level_ ==
                MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE &&
              old_pressure ==
                MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL) {
     // When we reducing the pressure level from critical to moderate, we
     // restart the timeout and do not send another notification.
     moderate_pressure_repeat_count_ = 0;
     return;
   }
   moderate_pressure_repeat_count_ = 0;
-  MemoryPressureListener::NotifyMemoryPressure(current_memory_pressure_level_);
+  dispatch_callback_.Run(current_memory_pressure_level_);
 }
 
 // Gets the used ChromeOS memory in percent.
 int MemoryPressureMonitor::GetUsedMemoryInPercent() {
   base::SystemMemoryInfoKB info;
   if (!base::GetSystemMemoryInfo(&info)) {
     VLOG(1) << "Cannot determine the free memory of the system.";
     return 0;
   }
   // TODO(skuhne): Instead of adding the kernel memory pressure calculation
@@ skipping 20 matching lines @@
 
   // Available memory is the sum of free, swap and easy reclaimable memory.
   int available_memory =
       info.free + info.swap_free / kSwapWeight + file_memory;
 
   DCHECK(available_memory < total_memory);
   int percentage = ((total_memory - available_memory) * 100) / total_memory;
   return percentage;
 }
 
+void MemoryPressureMonitor::SetDispatchCallback(
+    const DispatchCallback& callback) {
+  dispatch_callback_ = callback;
+}
+
 }  // namespace chromeos
 }  // namespace base