Adding flag to specify the used memory pressure strategy

base/chromeos/memory_pressure_observer_chromeos.cc

Index: base/chromeos/memory_pressure_observer_chromeos.cc
diff --git a/base/chromeos/memory_pressure_observer_chromeos.cc b/base/chromeos/memory_pressure_observer_chromeos.cc
index 4da7d24bfdb75a38bb9be99b5877819b8c5ed3bf..af9b50d3ab138277531c2575747ce1808c87a65f 100644
--- a/base/chromeos/memory_pressure_observer_chromeos.cc
+++ b/base/chromeos/memory_pressure_observer_chromeos.cc
@@ -24,25 +24,38 @@ const int kModerateMemoryPressureCooldown =
     kModerateMemoryPressureCooldownMs / kMemoryPressureIntervalMs;
 
 // Threshold constants to emit pressure events.
-const int kMemoryPressureModerateThresholdPercent = 70;
-const int kMemoryPressureCriticalThresholdPercent = 90;
+const int kNormalMemoryPressureModerateThresholdPercent = 60;
+const int kNormalMemoryPressureCriticalThresholdPercent = 90;
+const int kAggressiveMemoryPressureModerateThresholdPercent = 35;
+const int kAggressiveMemoryPressureCriticalThresholdPercent = 70;
 
 // Converts free percent of memory into a memory pressure value.
 MemoryPressureListener::MemoryPressureLevel GetMemoryPressureLevelFromFillLevel(
-    int memory_fill_level) {
-  if (memory_fill_level < kMemoryPressureModerateThresholdPercent)
+    int actual_fill_level, int moderate_threshold, int critical_threshold) {
+  if (actual_fill_level < moderate_threshold)
     return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
-  return memory_fill_level < kMemoryPressureCriticalThresholdPercent ?
+  return actual_fill_level < critical_threshold ?
       MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE :
       MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL;
 }
 
 }  // namespace
 
-MemoryPressureObserverChromeOS::MemoryPressureObserverChromeOS()
+MemoryPressureObserverChromeOS::MemoryPressureObserverChromeOS(
+    MemoryPressureThresholds thresholds)
     : current_memory_pressure_level_(
         MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE),
       moderate_pressure_repeat_count_(0),
+      moderate_pressure_threshold_(
+          (thresholds == AGGRESSIVE_MODERATE_THRESHOLD ||

[Charlie Reis, 2015/01/21 17:42:05]

Might this be easier to read with helper functions, like
IsModerateThresholdAggressive(thresholds) or even
GetModerateThreshold(thresholds)?

[Mr4D (OOO till 08-26), 2015/01/21 18:52:14]

Done.

+           thresholds == AGGRESSIVE_THRESHOLDS)?
+               kAggressiveMemoryPressureModerateThresholdPercent :
+               kNormalMemoryPressureModerateThresholdPercent),
+      critical_pressure_threshold_(
+          (thresholds == AGGRESSIVE_CRITICAL_THRESHOLD ||
+           thresholds == AGGRESSIVE_THRESHOLDS)?
+               kAggressiveMemoryPressureCriticalThresholdPercent :
+               kNormalMemoryPressureCriticalThresholdPercent),
       weak_ptr_factory_(this) {
   StartObserving();
 }
@@ -74,7 +87,9 @@ void MemoryPressureObserverChromeOS::CheckMemoryPressure() {
   MemoryPressureListener::MemoryPressureLevel old_pressure =
       current_memory_pressure_level_;
   current_memory_pressure_level_ =
-      GetMemoryPressureLevelFromFillLevel(GetUsedMemoryInPercent());
+      GetMemoryPressureLevelFromFillLevel(GetUsedMemoryInPercent(),
+                                          moderate_pressure_threshold_,
+                                          critical_pressure_threshold_);
   // In case there is no memory pressure we do not notify.
   if (current_memory_pressure_level_ ==
       MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE) {