Removing the |MemoryPressureObserverChromeOS::MemoryPressureLevel| enum.

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 d991e3f16b10fa0709bf7141aaed7ac61e6d6c38..19699ed3713c2efab9b04393e6c81debb32c2aa2 100644
--- a/base/chromeos/memory_pressure_observer_chromeos.cc
+++ b/base/chromeos/memory_pressure_observer_chromeos.cc
@@ -15,16 +15,13 @@ namespace {
 const int kMemoryPressureIntervalInMS = 1000;
 
 // Converts free percent of memory into a memory pressure value.
-MemoryPressureObserverChromeOS::MemoryPressureLevel
-GetMemoryPressureLevelFromFillLevel(
+MemoryPressureListener::MemoryPressureLevel GetMemoryPressureLevelFromFillLevel(
     int memory_fill_level) {
-  if (memory_fill_level < 50)
-    return MemoryPressureObserverChromeOS::MEMORY_PRESSURE_LEVEL_LOW;
-  if (memory_fill_level < 75)
-    return MemoryPressureObserverChromeOS::MEMORY_PRESSURE_LEVEL_MODERATE;
+  if (memory_fill_level < 70)
+    return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
   if (memory_fill_level < 90)
-    return MemoryPressureObserverChromeOS::MEMORY_PRESSURE_LEVEL_HIGH;
-  return MemoryPressureObserverChromeOS::MEMORY_PRESSURE_LEVEL_CRITICAL;
+    return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE;
+  return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL;

[rmcilroy, 2014/12/17 15:21:49]

super nit (ignore if you like) - do this in an "else" block to keep the returns
on the same indentation level.

[Mr4D (OOO till 08-26), 2014/12/17 15:28:58]

Done.

 }
 
 // Gets the used ChromeOS memory in percent.
@@ -68,7 +65,8 @@ int GetUsedMemoryInPercent() {
 }  // namespace
 
 MemoryPressureObserverChromeOS::MemoryPressureObserverChromeOS()
-    : current_memory_pressure_level_(MEMORY_PRESSURE_LEVEL_LOW) {
+    : current_memory_pressure_level_(
+        MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE) {
   StartObserving();
 }
 
@@ -89,25 +87,20 @@ void MemoryPressureObserverChromeOS::StopObserving() {
 }
 
 void MemoryPressureObserverChromeOS::CheckMemoryPressure() {
-  MemoryPressureLevel old_pressure = current_memory_pressure_level_;
-  MemoryPressureLevel new_pressure =
+  MemoryPressureListener::MemoryPressureLevel old_pressure =
+      current_memory_pressure_level_;
+  MemoryPressureListener::MemoryPressureLevel new_pressure =
       GetMemoryPressureLevelFromFillLevel(GetUsedMemoryInPercent());
   if (old_pressure != new_pressure) {
     current_memory_pressure_level_ = new_pressure;
     switch (new_pressure) {
-      case MEMORY_PRESSURE_LEVEL_LOW:
+      case MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE:
         // The |MemoryPressureListener| does currently not support this.

[rmcilroy, 2014/12/17 15:21:49]

update comment to state that the MemoryPressureListener does not send a
notification for MEMORY_PRESSURE_LEVEL_NONE 

[Mr4D (OOO till 08-26), 2014/12/17 15:28:58]

Done.

         break;
-      case MEMORY_PRESSURE_LEVEL_MODERATE:
-        MemoryPressureListener::NotifyMemoryPressure(
-            MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE);
-        break;
-      case MEMORY_PRESSURE_LEVEL_HIGH:
-        // The |MemoryPressureListener| does currently not support this.
-        break;
-      case MEMORY_PRESSURE_LEVEL_CRITICAL:
-        MemoryPressureListener::NotifyMemoryPressure(
-            MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL);
+      case MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE:

[rmcilroy, 2014/12/17 15:21:49]

it doesn't seem worth while doing this in a switch when everything should just
fall-through.  Maybe just do:

if (new_pressure == MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE) {
   // <comment...>
   return;
}
MemoryPressureListener::NotifyMemoryPressure(new_pressure);

[Mr4D (OOO till 08-26), 2014/12/17 15:28:58]

I did this on purpose since I want to enforce to look at this code when we add
more states. But done.

[rmcilroy, 2014/12/17 15:31:26]

Agreed that this would be useful but as discussed offline I don't think this is
the right place for it, maybe a unittest instead would work better.

+        // Fallthrough
+      case MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL:
+        MemoryPressureListener::NotifyMemoryPressure(new_pressure);
         break;
     }
   }