Move RenderLayerCompositor trigger caching to be when settings change

Source/core/frame/Settings.in

 # Defines properties which are available on the Settings object.
 #
 # Please think carefully before adding a new Setting.  Some questions to
 # consider are:
 # - Should this be a RuntimeEnabledFeature instead? Settings are for things
 #   which we support either values of at runtime.  Features are set at renderer
 #   process startup and are never changed. Features also tend to be set to a
 #   value based on the platform or the stability of the code in question, where
 #   as settings both codepaths need to be stable.
 # - How will you ensure test coverage of all relevant values of your setting?
@@ skipping 51 matching lines @@
 localStorageEnabled initial=false
 allowUniversalAccessFromFileURLs initial=true
 allowFileAccessFromFileURLs initial=true
 javaScriptCanOpenWindowsAutomatically initial=false
 supportsMultipleWindows initial=true
 javaScriptCanAccessClipboard initial=false
 shouldPrintBackgrounds initial=false
 shouldClearDocumentBackground initial=true
 
 textAreasAreResizable initial=false, invalidate=Style
-acceleratedCompositingEnabled initial=true, invalidate=Style
+acceleratedCompositingEnabled initial=true, invalidate=AcceleratedCompositing
 
 # Debugging feature used for accelerated compositing layers.
-showRepaintCounter initial=false, invalidate=Style
+showRepaintCounter initial=false, invalidate=AcceleratedCompositing
 
 shrinksStandaloneImagesToFit initial=true
 
 # FIXME: Does this do anything now that we don't support page cache?
 pageCacheSupportsPlugins initial=false
 
 needsSiteSpecificQuirks initial=false
 offlineWebApplicationCacheEnabled initial=false
 usesEncodingDetector initial=false
 allowScriptsToCloseWindows initial=false
 deferredFiltersEnabled initial=false
 regionBasedColumnsEnabled initial=false
 
 containerCullingEnabled initial=false
 
 # FIXME: This should really be disabled by default as it makes platforms that
 # don't support the feature download files they can't use by.
 # Leaving enabled for now to not change existing behavior.
 downloadableBinaryFontsEnabled initial=true
 
 xssAuditorEnabled initial=false
 unsafePluginPastingEnabled initial=true
 treatIPAddressAsDomain initial=false
 
-acceleratedCompositingFor3DTransformsEnabled initial=true
-acceleratedCompositingForVideoEnabled initial=true
-acceleratedCompositingForPluginsEnabled initial=true
-acceleratedCompositingForCanvasEnabled initial=true
-acceleratedCompositingForAnimationEnabled initial=true
-acceleratedCompositingForFiltersEnabled initial=false
+acceleratedCompositingFor3DTransformsEnabled initial=true, invalidate=AcceleratedCompositing
+acceleratedCompositingForVideoEnabled initial=true, invalidate=AcceleratedCompositing
+acceleratedCompositingForPluginsEnabled initial=true, invalidate=AcceleratedCompositing
+acceleratedCompositingForCanvasEnabled initial=true, invalidate=AcceleratedCompositing
+acceleratedCompositingForAnimationEnabled initial=true, invalidate=AcceleratedCompositing
+acceleratedCompositingForFiltersEnabled initial=false, invalidate=AcceleratedCompositing
 acceleratedCompositingForFixedPositionEnabled initial=false
-acceleratedCompositingForOverflowScrollEnabled initial=false
+acceleratedCompositingForOverflowScrollEnabled initial=false, invalidate=AcceleratedCompositing
 acceleratedCompositingForFixedRootBackgroundEnabled initial=false
-acceleratedCompositingForGpuRasterizationHintEnabled initial=false
+acceleratedCompositingForGpuRasterizationHintEnabled initial=false, invalidate=AcceleratedCompositing
 
-forceCompositingMode initial=false
+forceCompositingMode initial=false, invalidate=AcceleratedCompositing
 
 # Works only in conjunction with forceCompositingMode.
 # crbug.com/304900 tracks removal once enabled on all platforms.
-acceleratedCompositingForScrollableFramesEnabled initial=false
+acceleratedCompositingForScrollableFramesEnabled initial=false, invalidate=AcceleratedCompositing
 compositedScrollingForFramesEnabled initial=false
 
 # 3D canvas (WebGL) support.
 webGLEnabled initial=false
 
 webGLErrorsToConsoleEnabled initial=true
 privilegedWebGLExtensionsEnabled initial=false
 accelerated2dCanvasEnabled initial=false
 antialiased2dCanvasEnabled initial=true
 accelerated2dCanvasMSAASampleCount type=int, initial=0
@@ skipping 138 matching lines @@
 javaEnabled initial=false
 pluginsEnabled initial=false
 
 viewportEnabled initial=false, invalidate=ViewportDescription
 viewportMetaEnabled initial=false
 
 dnsPrefetchingEnabled initial=false, invalidate=DNSPrefetching
 
 touchEventEmulationEnabled initial=false
 
-
 # FIXME: This is a temporary flag and should be removed once
 # accelerated overflow scroll is ready (crbug.com/254111).
-compositorDrivenAcceleratedScrollingEnabled initial=false
+compositorDrivenAcceleratedScrollingEnabled initial=false, invalidate=AcceleratedCompositing
 
 # FIXME: This is a temporary flag and should be removed
 # when squashing is ready. (crbug.com/261605)
 layerSquashingEnabled initial=false
 
 # Clients that execute script should call ScriptController::canExecuteScripts()
 # instead of this function. ScriptController::canExecuteScripts() checks the
 # HTML sandbox, plug-in sandboxing, and other important details.
 scriptEnabled initial=false, invalidate=ScriptEnable
 
 # Compensates for poor text legibility on mobile devices. This value is
 # multiplied by the font scale factor when performing text autosizing of
 # websites that do not set an explicit viewport description.
 deviceScaleAdjustment type=double, initial=1.0, invalidate=TextAutosizing