[bfcache] Add bug number to TODO to finalize allowed features.

TBR=alexmos@chromium.org

Bug: 1015784
Change-Id: I37a127ef05490c1f847f0213eb1212dce87e0ebd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1868874Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Alexander Timin <altimin@chromium.org>
Commit-Queue: Lowell Manners <lowell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707344}

content/browser/frame_host/back_forward_cache_impl.cc

@@ -83,8 +83,8 @@ bool IsExtendedSupportEnabled() {
 }
 
 uint64_t GetDisallowedFeatures(RenderFrameHostImpl* rfh) {
-  // TODO(lowell): Finalize disallowed feature list, and test for each
-  // disallowed feature.
+  // TODO(https://crbug.com/1015784): Finalize disallowed feature list, and test
+  // for each disallowed feature.
   constexpr uint64_t kAlwaysDisallowedFeatures =
       ToFeatureBit(WebSchedulerTrackedFeature::kWebRTC) |
       ToFeatureBit(WebSchedulerTrackedFeature::kContainsPlugins) |