Revert "[WebNFC] Enable feature flag by default for Origin Trial"

This reverts commit 22b25dd3.

Reason for revert: NFC settings crash on Android L and M. (crbug/1055216)

Original change's description:
> [WebNFC] Enable feature flag by default for Origin Trial
>
> For the WebNFC Origin Trial the feature flag needs to be enabled by
> default and configured as "disable only" in runtime_features.cc so that
> it can still be used as a kill switch but will not enable the feature
> on sites which don't have a valid Origin Trial token.
>
> Bug: 1035048
> Change-Id: I139a79dd0f93013bc59d5023017b49c820532fb1
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2052198
> Commit-Queue: Reilly Grant <reillyg@chromium.org>
> Reviewed-by: Charlie Reis <creis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#743309}

TBR=creis@chromium.org,reillyg@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1035048, 1055216
Change-Id: I6617ee1b2bc6b3d1fb719d0454d4f8f4735bd44c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2070106Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743984}

content/child/runtime_features.cc

@@ -99,6 +99,11 @@ void SetRuntimeFeatureDefaultsForPlatform(
     WebRuntimeFeatures::EnableMediaSession(false);
 #endif
 
+#if defined(OS_ANDROID)
+  WebRuntimeFeatures::EnableWebNfc(
+      base::FeatureList::IsEnabled(features::kWebNfc));
+#endif
+
 #if defined(OS_ANDROID)
   // APIs for Web Authentication are not available prior to N.
   WebRuntimeFeatures::EnableWebAuth(
@@ -305,10 +310,6 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
            features::kBrowserVerifiedUserActivationMouse, kEnableOnly},
           {wf::EnablePercentBasedScrolling, features::kPercentBasedScrolling,
            kUseFeatureState},
-#if defined(OS_ANDROID)
-          {wf::EnableWebNfc,
-           features::kWebNfc, kDisableOnly},
-#endif
       };
   for (const auto& mapping : blinkFeatureToBaseFeatureMapping) {
     const bool featureEnabled =

content/public/common/content_features.cc

@@ -832,10 +832,9 @@ const base::Feature kWarmUpNetworkProcess{"WarmUpNetworkProcess",
 const base::Feature kForce60HzRefreshRate{"Force60HzRefreshRate",
                                           base::FEATURE_DISABLED_BY_DEFAULT};
 
-// Kill switch for the WebNFC feature. This feature can be enabled for all sites
-// using the kEnableExperimentalWebPlatformFeatures flag or by a particular site
-// if it includes an Origin Trial key.  https://w3c.github.io/web-nfc/
-const base::Feature kWebNfc{"WebNFC", base::FEATURE_ENABLED_BY_DEFAULT};
+// Controls whether the WebNFC API is enabled:
+// https://w3c.github.io/web-nfc/
+const base::Feature kWebNfc{"WebNFC", base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // defined(OS_ANDROID)
 
 #if defined(OS_CHROMEOS)