Adding crash keys for root_view, map size.

While the incidents of this bug are decreasing, we are still seeing it
somewhat on Windows. In each case, it seems the current gesture target
is no longer in the owners_map_.

Adding more keys to confirm whether the target is the root view or
not (seems most likely it isn't), and whether there are other views in
the map beyond the root view.

Bug: 824774
Change-Id: I99e777fb0d244ee80784a23332744089419f1d96
Reviewed-on: https://chromium-review.googlesource.com/1047192
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556457}

content/browser/renderer_host/render_widget_host_input_event_router.cc

@@ -1218,11 +1218,21 @@ void RenderWidgetHostInputEventRouter::DispatchTouchscreenGestureEvent(
   base::debug::SetCrashKeyString(
       target_ptr_key,
       base::StringPrintf("%p", touchscreen_gesture_target_.target));
+  static auto* root_ptr_key = base::debug::AllocateCrashKeyString(
+      "touchscreen-gesture-root-ptr", base::debug::CrashKeySize::Size64);
+  base::debug::SetCrashKeyString(root_ptr_key,
+                                 base::StringPrintf("%p", root_view));
   static auto* target_ptr_in_map_key = base::debug::AllocateCrashKeyString(
       "touchscreen-gesture-target-in-map", base::debug::CrashKeySize::Size32);
   base::debug::SetCrashKeyString(
       target_ptr_in_map_key,
       touchscreen_gesture_target_in_map_ ? "true" : "false");
+  static auto* map_size_key = base::debug::AllocateCrashKeyString(
+      "touchscreen-gesture-map-size", base::debug::CrashKeySize::Size32);
+  base::debug::SetCrashKeyString(
+      map_size_key,
+      base::StringPrintf("%u", static_cast<int>(owner_map_.size())));
+
   touchscreen_gesture_target_.target->ProcessGestureEvent(event, latency);
 }