Native memory histograms for the browser.

content/browser/browser_main_loop.h

Index: content/browser/browser_main_loop.h
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index 284ecf6bd7b3ef84aa97d0ee496664d09a052261..25e15a04c1fc03ced8f13b5487642df84edea712 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -49,6 +49,7 @@ class DeviceMonitorMac;
 // All functions are to be called only on the UI thread unless otherwise noted.
 class BrowserMainLoop {
  public:
+  class MemoryObserver;
   explicit BrowserMainLoop(const MainFunctionParams& parameters);
   virtual ~BrowserMainLoop();
 
@@ -131,6 +132,7 @@ class BrowserMainLoop {
   scoped_ptr<BrowserProcessSubThread> process_launcher_thread_;
   scoped_ptr<BrowserProcessSubThread> cache_thread_;
   scoped_ptr<BrowserProcessSubThread> io_thread_;
+  scoped_ptr<MemoryObserver> memory_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);
 };