Migrate ChromeOS to base::MemoryPressureMonitor

chrome/browser/browser_process_platform_part_chromeos.cc

Index: chrome/browser/browser_process_platform_part_chromeos.cc
diff --git a/chrome/browser/browser_process_platform_part_chromeos.cc b/chrome/browser/browser_process_platform_part_chromeos.cc
index 12d6ce6a97ccb52be49e23d9f53251945b1fb68a..8030f885c3ea571b4a04c74b62144433d0b2fbb5 100644
--- a/chrome/browser/browser_process_platform_part_chromeos.cc
+++ b/chrome/browser/browser_process_platform_part_chromeos.cc
@@ -22,6 +22,8 @@
 #include "chrome/browser/chromeos/system/timezone_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/common/memory_pressure_monitor_chromeos.h"
+#include "chromeos/chromeos_switches.h"
 #include "chromeos/geolocation/simple_geolocation_provider.h"
 #include "chromeos/timezone/timezone_resolver.h"
 #include "components/session_manager/core/session_manager.h"
@@ -95,8 +97,13 @@ session_manager::SessionManager* BrowserProcessPlatformPart::SessionManager() {
 chromeos::OomPriorityManager*
     BrowserProcessPlatformPart::oom_priority_manager() {
   DCHECK(CalledOnValidThread());
-  if (!oom_priority_manager_.get())
+  if (!oom_priority_manager_.get()) {

[Mr4D (OOO till 08-26), 2015/03/31 21:12:17]

I suppose this is temporary?

Also - I am not sure that this will work. I remember vaguely that I moved it to
content in order to have it accessible for various target situations.
+ there were several efforts going on to separate content from chrome and vice
versa (e.g. for AppShell, etc.). This was the reason for moving the observer
into base, since that is available for all.

Looking into processes it would be even more beneficial to have them in base.

+    if (chromeos::switches::MemoryPressureHandlingEnabled()) {

[Mr4D (OOO till 08-26), 2015/03/31 21:12:17]

What was the reason for not instantiating it with the first
MemoryPressureListener creation?

+      memory_pressure_monitor_.reset(new MemoryPressureMonitorChromeOS(
+          chromeos::switches::GetMemoryPressureThresholds()));
+    }
     oom_priority_manager_.reset(new chromeos::OomPriorityManager());
+  }
   return oom_priority_manager_.get();
 }