Make memory pressure notifier configurable

base/memory/memory_pressure_monitor_win.cc

Index: base/memory/memory_pressure_monitor_win.cc
diff --git a/base/memory/memory_pressure_monitor_win.cc b/base/memory/memory_pressure_monitor_win.cc
index 8ac66cec0880248cdea7107cd2c6b33806e4cdf4..a93b425e8228fbdd44e54899e96e6be53dd8db7e 100644
--- a/base/memory/memory_pressure_monitor_win.cc
+++ b/base/memory/memory_pressure_monitor_win.cc
@@ -82,6 +82,8 @@ MemoryPressureMonitor::MemoryPressureMonitor()
       current_memory_pressure_level_(
           MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE),
       moderate_pressure_repeat_count_(0),
+      dispatch_callback_(
+          base::Bind(&MemoryPressureListener::NotifyMemoryPressure)),
       weak_ptr_factory_(this) {
   InferThresholds();
   StartObserving();
@@ -94,6 +96,8 @@ MemoryPressureMonitor::MemoryPressureMonitor(int moderate_threshold_mb,
       current_memory_pressure_level_(
           MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE),
       moderate_pressure_repeat_count_(0),
+      dispatch_callback_(
+          base::Bind(&MemoryPressureListener::NotifyMemoryPressure)),
       weak_ptr_factory_(this) {
   DCHECK_GE(moderate_threshold_mb_, critical_threshold_mb_);
   DCHECK_LE(0, critical_threshold_mb_);
@@ -198,7 +202,7 @@ void MemoryPressureMonitor::CheckMemoryPressure() {
   // happen for moderate and critical pressure levels.
   DCHECK_NE(MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE,
             current_memory_pressure_level_);
-  MemoryPressureListener::NotifyMemoryPressure(current_memory_pressure_level_);
+  dispatch_callback_.Run(current_memory_pressure_level_);
 }
 
 void MemoryPressureMonitor::CheckMemoryPressureAndRecordStatistics() {
@@ -250,5 +254,10 @@ bool MemoryPressureMonitor::GetSystemMemoryStatus(
   return true;
 }
 
+void MemoryPressureMonitor::SetDispatchCallback(
+    const DispatchCallback& callback) {
+  dispatch_callback_ = callback;
+}
+
 }  // namespace win
 }  // namespace base