Rename PageLifecycleObserver to PageVisibilityObserver

third_party/WebKit/Source/core/core.gypi

 {
     'includes': [
         'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/KeyframeEffect.idl',
             'animation/EffectModel.idl',
             'animation/AnimationEffectReadOnly.idl',
@@ skipping 1970 matching lines @@
             'page/EventSourceParser.h',
             'page/EventWithHitTestResults.h',
             'page/FocusController.cpp',
             'page/FrameTree.cpp',
             'page/NetworkStateNotifier.cpp',
             'page/NetworkStateNotifier.h',
             'page/Page.cpp',
             'page/Page.h',
             'page/PageAnimator.cpp',
             'page/PageAnimator.h',
-            'page/PageLifecycleNotifier.cpp',
-            'page/PageLifecycleNotifier.h',
-            'page/PageLifecycleObserver.h',
+            'page/PageVisibilityNotifier.cpp',
+            'page/PageVisibilityNotifier.h',
+            'page/PageVisibilityObserver.h',
             'page/PagePopupClient.cpp',
             'page/PagePopupClient.h',
             'page/PagePopupController.cpp',
             'page/PagePopupController.h',
             'page/PagePopupSupplement.cpp',
             'page/PagePopupSupplement.h',
             'page/PageVisibilityState.cpp',
             'page/PointerLockController.cpp',
             'page/PointerLockController.h',
             'page/PopupOpeningObserver.h',
@@ skipping 2203 matching lines @@
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'timing/PerformanceBaseTest.cpp',
             'timing/PerformanceObserverTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'workers/WorkerThreadTestHelper.h',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }