Add missing .h files to .gn files that have a .cc file next to it in the gn file already.

third_party/WebKit/Source/core/timing/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//third_party/WebKit/Source/core/core.gni")
 
 blink_core_sources("timing") {
   sources = [
     "DOMWindowPerformance.cpp",
     "DOMWindowPerformance.h",
     "MemoryInfo.cpp",
+    "MemoryInfo.h",
     "Performance.cpp",
     "Performance.h",
     "PerformanceBase.cpp",
     "PerformanceBase.h",
     "PerformanceEntry.cpp",
     "PerformanceEntry.h",
     "PerformanceLongTaskTiming.cpp",
     "PerformanceLongTaskTiming.h",
     "PerformanceMark.h",
     "PerformanceMeasure.h",
     "PerformanceNavigation.cpp",
     "PerformanceNavigation.h",
     "PerformanceNavigationTiming.cpp",
     "PerformanceNavigationTiming.h",
     "PerformanceObserver.cpp",
     "PerformanceObserver.h",
     "PerformanceObserverEntryList.cpp",
     "PerformanceObserverEntryList.h",
     "PerformancePaintTiming.cpp",
     "PerformancePaintTiming.h",
     "PerformanceResourceTiming.cpp",
     "PerformanceResourceTiming.h",
     "PerformanceTiming.cpp",
     "PerformanceTiming.h",
     "PerformanceUserTiming.cpp",
     "PerformanceUserTiming.h",
     "SharedWorkerPerformance.cpp",
+    "SharedWorkerPerformance.h",
     "TaskAttributionTiming.cpp",
     "TaskAttributionTiming.h",
     "WorkerGlobalScopePerformance.cpp",
     "WorkerGlobalScopePerformance.h",
     "WorkerPerformance.cpp",
     "WorkerPerformance.h",
   ]
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 }