Enable ReportingObserver, Deprecation Reports by default.

Intent to ship: https://groups.google.com/a/chromium.org/forum/#!topic/Blink-dev/z4CWYor4UpQ

Bug: 731810
Change-Id: I8146e6af6edba7b0ab844a47afb4d889b081e117
Reviewed-on: https://chromium-review.googlesource.com/1110351
Commit-Queue: Paul Meyer <paulmeyer@chromium.org>
Reviewed-by: Rick Byers <rbyers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569600}

third_party/WebKit/LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt

@@ -4836,6 +4836,11 @@ interface RemotePlayback : EventTarget
     setter onconnect
     setter onconnecting
     setter ondisconnect
+interface ReportingObserver
+    attribute @@toStringTag
+    method constructor
+    method disconnect
+    method observe
 interface Request
     attribute @@toStringTag
     getter bodyUsed

third_party/blink/renderer/core/frame/deprecation_report_body.idl

@@ -6,7 +6,7 @@
 
 [
     NoInterfaceObject,
-    RuntimeEnabled=ReportingObserver
+    RuntimeEnabled=DeprecationReporting
 ] interface DeprecationReportBody : ReportBody {
   readonly attribute DOMString id;
   readonly attribute Date? anticipatedRemoval;

third_party/blink/renderer/core/frame/intervention_report_body.idl

@@ -6,7 +6,7 @@
 
 [
     NoInterfaceObject,
-    RuntimeEnabled=ReportingObserver
+    RuntimeEnabled=InterventionReporting
 ] interface InterventionReportBody : ReportBody {
   // TODO(paulmeyer): Add additional data, such as id.
   readonly attribute DOMString message;

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -371,7 +371,7 @@
     },
     {
       name: "DeprecationReporting",
-      status: "experimental",
+      status: "stable",
     },
     {
       name: "DesktopCaptureDisableLocalEchoControl",
@@ -613,6 +613,10 @@
       name: "IntersectionObserverV2",
       settable_from_internals: true,
     },
+    {
+      name: "InterventionReporting",
+      status: "experimental",
+    },
     {
       // Tracks "jank" from layout objects changing their visual location
       // between animation frames (see crbug.com/581518).
@@ -1041,7 +1045,8 @@
     },
     {
       name: "ReportingObserver",
-      status: "experimental",
+      implied_by: ["DeprecationReporting", "InterventionReporting"],
+      status: "stable",
     },
     {
       name: "RequestIsHistoryNavigation",