[Mac] Report statistics more regularly in Mac memory pressure monitor

chrome/browser/chromeos/resource_reporter/resource_reporter_unittest.cc

 // Copyright 2015 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 <stddef.h>
 #include <stdint.h>
 
 #include <limits>
 #include <map>
 #include <string>
@@ skipping 103 matching lines @@
         memory_pressure_level_(
             MemoryPressureLevel::MEMORY_PRESSURE_LEVEL_NONE) {}
   ~DummyMemoryPressureMonitor() override {}
 
   void SetAndNotifyMemoryPressure(MemoryPressureLevel level) {
     memory_pressure_level_ = level;
     base::MemoryPressureListener::SimulatePressureNotification(level);
   }
 
   // base::CriticalMemoryPressureMonitor:
-  MemoryPressureLevel GetCurrentPressureLevel() const override {
+  MemoryPressureLevel GetCurrentPressureLevel() override {
     return memory_pressure_level_;
   }
   void SetDispatchCallback(const DispatchCallback& callback) override {}
 
  private:
   MemoryPressureLevel memory_pressure_level_;
 
   DISALLOW_COPY_AND_ASSIGN(DummyMemoryPressureMonitor);
 };
 
@@ skipping 154 matching lines @@
 
   // Make sure you have the right info about the Browser and GPU process.
   EXPECT_EQ(resource_reporter()->last_browser_process_cpu_, kBrowserProcessCpu);
   EXPECT_EQ(resource_reporter()->last_browser_process_memory_,
             kBrowserProcessMemory);
   EXPECT_EQ(resource_reporter()->last_gpu_process_cpu_, kGpuProcessCpu);
   EXPECT_EQ(resource_reporter()->last_gpu_process_memory_, kGpuProcessMemory);
 }
 
 }  // namespace chromeos