Extract simpler classes for observing context lifecycle and observe Page lifecycle inNavigatorVibra…

Source/core/page/Page.h

Index: Source/core/page/Page.h
diff --git a/Source/core/page/Page.h b/Source/core/page/Page.h
index e8579638dcad3f0361629283144eadd7397490dd..9de5062e66cc0b823796687a0743fcdedc775ca0 100644
--- a/Source/core/page/Page.h
+++ b/Source/core/page/Page.h
@@ -21,6 +21,7 @@
 #ifndef Page_h
 #define Page_h
 
+#include "core/dom/LifecycleContext.h"
 #include "core/dom/ViewportArguments.h"
 #include "core/page/LayoutMilestones.h"
 #include "core/page/PageVisibilityState.h"
@@ -63,6 +64,7 @@ class InspectorController;
 class Node;
 class PageConsole;
 class PageGroup;
+class PageLifecycleNotifier;
 class PlatformMouseEvent;
 class PluginData;
 class PointerLockController;
@@ -92,7 +94,7 @@ struct ArenaSize {
     size_t allocated;
 };
 
-class Page : public Supplementable<Page> {
+class Page : public Supplementable<Page>, public LifecycleContext {
     WTF_MAKE_NONCOPYABLE(Page);
     friend class Settings;
 public:
@@ -268,6 +270,9 @@ public:
     void removeMultisamplingChangedObserver(MultisamplingChangedObserver*);
     void multisamplingChanged();
 
+protected:
+    PageLifecycleNotifier* lifecycleNotifier();
+
 private:
     void initGroup();
 
@@ -279,6 +284,8 @@ private:
 
     void setTimerAlignmentInterval(double);
 
+    virtual PassOwnPtr<LifecycleNotifier> createLifecycleNotifier() OVERRIDE;
+
     OwnPtr<AutoscrollController> m_autoscrollController;
     OwnPtr<Chrome> m_chrome;
     OwnPtr<DragCaretController> m_dragCaretController;