First version of PerformanceObserver

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 358 matching lines @@
             'svg/SVGViewElement.idl',
             'svg/SVGViewSpec.idl',
             'svg/SVGZoomEvent.idl',
             'timing/MemoryInfo.idl',
             'timing/Performance.idl',
             'timing/PerformanceCompositeTiming.idl',
             'timing/PerformanceEntry.idl',
             'timing/PerformanceMark.idl',
             'timing/PerformanceMeasure.idl',
             'timing/PerformanceNavigation.idl',
+            'timing/PerformanceObserver.idl',
+            'timing/PerformanceObserverEntryList.idl',
             'timing/PerformanceRenderTiming.idl',
             'timing/PerformanceResourceTiming.idl',
             'timing/PerformanceTiming.idl',
             'timing/WorkerPerformance.idl',
             'workers/SharedWorker.idl',
             'workers/Worker.idl',
             'workers/WorkerConsole.idl',
             'workers/WorkerLocation.idl',
             'xml/DOMParser.idl',
             'xml/XMLSerializer.idl',
@@ skipping 1625 matching lines @@
             'timing/PerformanceBase.cpp',
             'timing/PerformanceBase.h',
             'timing/PerformanceCompositeTiming.cpp',
             'timing/PerformanceCompositeTiming.h',
             'timing/PerformanceEntry.cpp',
             'timing/PerformanceEntry.h',
             'timing/PerformanceMark.h',
             'timing/PerformanceMeasure.h',
             'timing/PerformanceNavigation.cpp',
             'timing/PerformanceNavigation.h',
+            'timing/PerformanceObserver.cpp',
+            'timing/PerformanceObserver.h',
+            'timing/PerformanceObserverCallback.h',
+            'timing/PerformanceObserverEntryList.cpp',
+            'timing/PerformanceObserverEntryList.h',
             'timing/PerformanceRenderTiming.cpp',
             'timing/PerformanceRenderTiming.h',
             'timing/PerformanceResourceTiming.cpp',
             'timing/PerformanceResourceTiming.h',
             'timing/PerformanceTiming.cpp',
             'timing/PerformanceTiming.h',
             'timing/PerformanceUserTiming.cpp',
             'timing/PerformanceUserTiming.h',
             'timing/SharedWorkerPerformance.cpp',
             'timing/WorkerGlobalScopePerformance.cpp',
@@ skipping 1459 matching lines @@
             'events/WheelEventInit.idl',
             'fileapi/BlobPropertyBag.idl',
             'fileapi/FilePropertyBag.idl',
             'frame/ScrollOptions.idl',
             'frame/ScrollToOptions.idl',
             'html/MediaKeyEventInit.idl',
             'html/canvas/CanvasContextCreationAttributes.idl',
             'html/track/TrackEventInit.idl',
             'input/InputDeviceInit.idl',
             'page/EventSourceInit.idl',
+            'timing/PerformanceObserverInit.idl',
         ],
         'generated_core_dictionary_files': [
             '<(blink_core_output_dir)/animation/KeyframeEffectOptions.cpp',
             '<(blink_core_output_dir)/animation/KeyframeEffectOptions.h',
             '<(blink_core_output_dir)/animation/ComputedTimingProperties.cpp',
             '<(blink_core_output_dir)/animation/ComputedTimingProperties.h',
             '<(blink_core_output_dir)/css/FontFaceDescriptors.cpp',
             '<(blink_core_output_dir)/css/FontFaceDescriptors.h',
             '<(blink_core_output_dir)/css/FontFaceSetLoadEventInit.cpp',
             '<(blink_core_output_dir)/css/FontFaceSetLoadEventInit.h',
@@ skipping 66 matching lines @@
             '<(blink_core_output_dir)/html/MediaKeyEventInit.cpp',
             '<(blink_core_output_dir)/html/MediaKeyEventInit.h',
             '<(blink_core_output_dir)/html/canvas/CanvasContextCreationAttributes.cpp',
             '<(blink_core_output_dir)/html/canvas/CanvasContextCreationAttributes.h',
             '<(blink_core_output_dir)/html/track/TrackEventInit.cpp',
             '<(blink_core_output_dir)/html/track/TrackEventInit.h',
             '<(blink_core_output_dir)/input/InputDeviceInit.cpp',
             '<(blink_core_output_dir)/input/InputDeviceInit.h',
             '<(blink_core_output_dir)/page/EventSourceInit.cpp',
             '<(blink_core_output_dir)/page/EventSourceInit.h',
+            '<(blink_core_output_dir)/timing/PerformanceObserverInit.cpp',
+            '<(blink_core_output_dir)/timing/PerformanceObserverInit.h',
         ],
         'core_testing_dictionary_idl_files': [
             'testing/InternalDictionary.idl',
             'testing/InternalDictionaryDerived.idl',
             'testing/PluginPlaceholderOptions.idl',
         ],
         'webcore_testing_idl_files': [
             'testing/DictionaryTest.idl',
             'testing/GCObservation.idl',
             'testing/GarbageCollectedScriptWrappable.idl',
@@ skipping 223 matching lines @@
             'style/OutlineValueTest.cpp',
             'style/SVGComputedStyleTest.cpp',
             'svg/UnsafeSVGAttributeSanitizationTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }