Rename OS-specific MemoryPressureMonitor implementations.

base/chromeos/memory_pressure_monitor.h

Index: base/chromeos/memory_pressure_monitor.h
diff --git a/base/chromeos/memory_pressure_monitor_chromeos.h b/base/chromeos/memory_pressure_monitor.h
similarity index 83%
rename from base/chromeos/memory_pressure_monitor_chromeos.h
rename to base/chromeos/memory_pressure_monitor.h
index 45855ebc01a691ae94896952810c14103f72043d..bed1ec39f6ac893e172c5bdb1d7ba4b808398b55 100644
--- a/base/chromeos/memory_pressure_monitor_chromeos.h
+++ b/base/chromeos/memory_pressure_monitor.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef BASE_CHROMEOS_MEMORY_PRESSURE_MONITOR_CHROMEOS_H_
-#define BASE_CHROMEOS_MEMORY_PRESSURE_MONITOR_CHROMEOS_H_
+#ifndef BASE_CHROMEOS_MEMORY_PRESSURE_MONITOR_H_
+#define BASE_CHROMEOS_MEMORY_PRESSURE_MONITOR_H_
 
 #include "base/base_export.h"
 #include "base/files/scoped_file.h"
@@ -15,17 +15,18 @@
 #include "base/timer/timer.h"
 
 namespace base {
+namespace chromeos {
 
 class TestMemoryPressureMonitor;
 
 ////////////////////////////////////////////////////////////////////////////////
-// MemoryPressureMonitorChromeOS
+// MemoryPressureMonitor
 //
 // A class to handle the observation of our free memory. It notifies the
 // MemoryPressureListener of memory fill level changes, so that it can take
 // action to reduce memory resources accordingly.
 //
-class BASE_EXPORT MemoryPressureMonitorChromeOS : public MemoryPressureMonitor {
+class BASE_EXPORT MemoryPressureMonitor : public base::MemoryPressureMonitor {

[Nico, 2015/05/14 20:03:37]

Having the same class name in slightly different namespaces is super ugly imho.
This is as far as I know not one of the patterns we usually use.

Usual patterns are:
* Have a single class base::MemoryPressureMonitor, spread its implementation
over various files (xplat stuff in mpm.cc, then per-platform stuff in mpm_mac.cc
etc), e.g. launch.cc
* Have an interface class with per-os subclasses, give the interface a Create()
method that opaquely returns an instance of the subclass (e.g.
CreateWebContentsView() and WebContentsView + subclasses)
* A cross-platform function that then instantiated completely distinct types
behind the scenes (e.g. chrome::ShowTaskManager())

  public:
   using GetUsedMemoryInPercentCallback = int (*)();
 
@@ -49,8 +50,8 @@ class BASE_EXPORT MemoryPressureMonitorChromeOS : public MemoryPressureMonitor {
     THRESHOLD_AGGRESSIVE = 4
   };
 
-  explicit MemoryPressureMonitorChromeOS(MemoryPressureThresholds thresholds);
-  ~MemoryPressureMonitorChromeOS() override;
+  explicit MemoryPressureMonitor(MemoryPressureThresholds thresholds);
+  ~MemoryPressureMonitor() override;
 
   // Redo the memory pressure calculation soon and call again if a critical
   // memory pressure prevails. Note that this call will trigger an asynchronous
@@ -61,6 +62,10 @@ class BASE_EXPORT MemoryPressureMonitorChromeOS : public MemoryPressureMonitor {
   MemoryPressureListener::MemoryPressureLevel GetCurrentPressureLevel() const
       override;
 
+  // Returns a type-casted version of the current memory pressure monitor. A
+  // simple wrapper to base::MemoryPressureMonitor::Get.
+  static MemoryPressureMonitor* Get();
+
  private:
   friend TestMemoryPressureMonitor;
   // Starts observing the memory fill level.
@@ -90,7 +95,7 @@ class BASE_EXPORT MemoryPressureMonitorChromeOS : public MemoryPressureMonitor {
 
   // A periodic timer to check for resource pressure changes. This will get
   // replaced by a kernel triggered event system (see crbug.com/381196).
-  base::RepeatingTimer<MemoryPressureMonitorChromeOS> timer_;
+  base::RepeatingTimer<MemoryPressureMonitor> timer_;
 
   // To slow down the amount of moderate pressure event calls, this counter
   // gets used to count the number of events since the last event occured.
@@ -103,11 +108,12 @@ class BASE_EXPORT MemoryPressureMonitorChromeOS : public MemoryPressureMonitor {
   // File descriptor used to detect low memory condition.
   ScopedFD low_mem_file_;
 
-  base::WeakPtrFactory<MemoryPressureMonitorChromeOS> weak_ptr_factory_;
+  base::WeakPtrFactory<MemoryPressureMonitor> weak_ptr_factory_;
 
-  DISALLOW_COPY_AND_ASSIGN(MemoryPressureMonitorChromeOS);
+  DISALLOW_COPY_AND_ASSIGN(MemoryPressureMonitor);
 };
 
+}  // namespace chromeos
 }  // namespace base
 
-#endif  // BASE_CHROMEOS_MEMORY_PRESSURE_MONITOR_CHROMEOS_H_
+#endif  // BASE_CHROMEOS_MEMORY_PRESSURE_MONITOR_H_