Make it clear that WebCoalescedInputEvent represents all event types

The current comment suggests that it does, but it seems worthwhile to
make it explicit given that the name of the event might suggest
otherwise.

Change-Id: Ie0ab5a95a462e9e493336644fa1d7f4ecd5edc42
Reviewed-on: https://chromium-review.googlesource.com/c/1340859Reviewed-by: Navid Zolghadr <nzolghadr@chromium.org>
Reviewed-by: Nate Chapin <japhet@chromium.org>
Commit-Queue: Nate Chapin <japhet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609509}

third_party/blink/public/platform/web_coalesced_input_event.h

@@ -14,8 +14,9 @@
 
 namespace blink {
 
-// This class is representing a polymorphic WebInputEvent structure with its
-// coalesced events. The event could be any events defined in WebInputEvent.h.
+// This class represents a polymorphic WebInputEvent structure with its
+// coalesced events. The event could be any event defined in WebInputEvent.h,
+// including those that cannot be coalesced.
 class BLINK_PLATFORM_EXPORT WebCoalescedInputEvent {
  public:
   explicit WebCoalescedInputEvent(const WebInputEvent&);