Media Capabilities: allow API to be used via Origin Trial.

Bug: 690364
Change-Id: I218ca3455dc9c838f798e96e89fdb5c3899e918e
Reviewed-on: https://chromium-review.googlesource.com/768669
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517810}

third_party/WebKit/Source/modules/media_capabilities/MediaCapabilities.idl

@@ -6,7 +6,7 @@
 
 [
     Exposed=Window,
-    RuntimeEnabled=MediaCapabilities
+    OriginTrialEnabled=MediaCapabilities
 ] interface MediaCapabilities {
     [CallWith=ScriptState] Promise<MediaCapabilitiesInfo> decodingInfo(MediaDecodingConfiguration configuration);
     [CallWith=ScriptState] Promise<MediaCapabilitiesInfo> encodingInfo(

third_party/WebKit/Source/modules/media_capabilities/MediaCapabilitiesInfo.idl

@@ -6,7 +6,7 @@
 
 [
     Exposed=Window,
-    RuntimeEnabled=MediaCapabilities
+    OriginTrialEnabled=MediaCapabilities
 ] interface MediaCapabilitiesInfo {
     readonly attribute boolean supported;
     readonly attribute boolean smooth;

third_party/WebKit/Source/modules/media_capabilities/NavigatorMediaCapabilities.idl

@@ -7,7 +7,7 @@
 [
     Exposed=Window,
     ImplementedAs=NavigatorMediaCapabilities,
-    RuntimeEnabled=MediaCapabilities
+    OriginTrialEnabled=MediaCapabilities
 ] partial interface Navigator {
     [SameObject] readonly attribute MediaCapabilities mediaCapabilities;
 };

third_party/WebKit/Source/platform/runtime_enabled_features.json5

@@ -564,6 +564,7 @@
     },
     {
       name: "MediaCapabilities",
+      origin_trial_feature_name: "MediaCapabilities",
       status: "experimental",
     },
     {