Update HoverButtons to trigger on both left and right click.

Bug: 997151
Change-Id: I8cac4c9f56a271201de62af0d250365372f1a95d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1784967Reviewed-by: Peter Boström <pbos@chromium.org>
Commit-Queue: Charlene Yan <cyan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693412}

chrome/browser/ui/views/hover_button.cc

@@ -12,6 +12,7 @@
 #include "chrome/browser/ui/views/chrome_layout_provider.h"
 #include "chrome/browser/ui/views/chrome_typography.h"
 #include "chrome/browser/ui/views/hover_button_controller.h"
+#include "ui/events/event_constants.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/views/animation/ink_drop_impl.h"
@@ -87,6 +88,8 @@ HoverButton::HoverButton(views::ButtonListener* button_listener,
 
   SetInkDropMode(InkDropMode::ON);
 
+  set_triggerable_event_flags(ui::EF_LEFT_MOUSE_BUTTON |
+                              ui::EF_RIGHT_MOUSE_BUTTON);
   button_controller()->set_notify_action(
       views::ButtonController::NotifyAction::NOTIFY_ON_RELEASE);
 }