[SubresourceFilter] Fix comment in throttle manager header

The comment refers to a "Delegate" class that is actually
SubresourceFilterClient.

Bug: 1116095
Change-Id: I1fc0d00149bd640b19f7f42c98e7990cecad171f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2435111Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811710}

components/subresource_filter/content/browser/content_subresource_filter_throttle_manager.h

@@ -42,10 +42,11 @@ class SubresourceFilterClient;
 // within a given WebContents. It contains a mapping of all activated
 // RenderFrameHosts, along with their associated DocumentSubresourceFilters.
 //
-// The class is designed to be used by a Delegate, which shares lifetime with
-// this class (aka the typical lifetime of a WebContentsObserver). The delegate
-// will be notified of the first disallowed subresource load for a top level
-// navgation, and has veto power for frame activation.
+// The class is designed to be used by a SubresourceFilterClient instance that
+// shares lifetime with this class (aka the typical lifetime of a
+// WebContentsObserver). The client will be notified of the first disallowed
+// subresource load for a top level navgation, and has veto power for frame
+// activation.
 class ContentSubresourceFilterThrottleManager
     : public content::WebContentsObserver,
       public mojom::SubresourceFilterHost,