Add temp peer_connection_interface include rtc_base/event.h

This fixes the WebRTC roll in Chrome, which was failing because the
//third_party/nearby library was transively including Chromes //base/check
via WebRTC overrides by including
api/peer_connection_interface.h
which included api/proxy.h
which included rtc_base/event.h
which was overrided in webrtc_overrides.

This override contains an include to base/check.h.

Adding a temporary dependency on event.h fixes this for now. This can be
removed once https://crbug.com/1212611 is fixed.

Bug: None
Change-Id: Id372e0737664d4a94ade0f75ae5fcf21f3db929f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/219630
Reviewed-by: Tommi <tommi@webrtc.org>
Commit-Queue: Evan Shrubsole <eshr@google.com>
Cr-Commit-Position: refs/heads/master@{#34098}
diff --git a/api/DEPS b/api/DEPS
index 1d3d43f..afec84d 100644
--- a/api/DEPS
+++ b/api/DEPS
@@ -130,6 +130,8 @@
     "+media/base/media_engine.h",
     "+p2p/base/port.h",
     "+p2p/base/port_allocator.h",
+    # TODO(https://crbug.com/1212611) Remove once includes fixed in nearby.
+    "+rtc_base/event.h",
     "+rtc_base/network.h",
     "+rtc_base/network_constants.h",
     "+rtc_base/network_monitor_factory.h",
diff --git a/api/peer_connection_interface.h b/api/peer_connection_interface.h
index 892e84e..75c4d3c 100644
--- a/api/peer_connection_interface.h
+++ b/api/peer_connection_interface.h
@@ -125,6 +125,8 @@
 // PortAllocator in the PeerConnection api. This will let us remove nogncheck.
 #include "p2p/base/port.h"            // nogncheck
 #include "p2p/base/port_allocator.h"  // nogncheck
+// TODO(https://crbug.com/1212611) Remove once includes fixed in nearby.
+#include "rtc_base/event.h"
 #include "rtc_base/network.h"
 #include "rtc_base/network_constants.h"
 #include "rtc_base/network_monitor_factory.h"