Compile core/input/ with -Wshadow.

Bug: 294205
Change-Id: I7dea7045db9c4c3e25c0fbadc5f0ecd4f369c3bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2461123Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815616}

third_party/blink/renderer/core/input/BUILD.gn

@@ -5,6 +5,8 @@
 import("//third_party/blink/renderer/core/core.gni")
 
 blink_core_sources("input") {
+  configs += [ "//build/config/compiler:noshadowing" ]
+
   sources = [
     "boundary_event_dispatcher.cc",
     "boundary_event_dispatcher.h",

third_party/blink/renderer/core/input/pointer_event_manager.cc

@@ -602,15 +602,16 @@ WebInputEventResult PointerEventManager::HandlePointerEvent(
                  event_handling_util::ShouldDiscardEventTargetingFrame(
                      event, *pointer_event_target.target_frame);
   if (discard) {
-    PointerEvent* pointer_event = pointer_event_factory_.Create(
+    PointerEvent* core_pointer_event = pointer_event_factory_.Create(
         event, coalesced_events, predicted_events,
         pointer_event_target.target_element
             ? pointer_event_target.target_element->GetDocument().domWindow()
             : nullptr);
-    SendTouchPointerEvent(pointer_event_target.target_element,
-                          pointer_event_factory_.CreatePointerCancelEvent(
-                              pointer_event->pointerId(), event.TimeStamp()),
-                          event.hovering);
+    SendTouchPointerEvent(
+        pointer_event_target.target_element,
+        pointer_event_factory_.CreatePointerCancelEvent(
+            core_pointer_event->pointerId(), event.TimeStamp()),
+        event.hovering);
 
     WebPointerEvent pointer_cancel_event;
     pointer_cancel_event.pointer_type = event.pointer_type;