surfaceflinger: use std::queue for mPendingEvents

Replace Vector by std::queue for mPendingEvents.  It is used for
pending hotplug events, which happen rarely and are consumed one by
one quickly by an RT thread.  std::queue is likely no better than
std::vector in that scenario, but is more expressive.

Bug: 115738279
Test: boots
Change-Id: Ia906a7f08ecbe6d5534cd6ec42e5af2ac865a911
diff --git a/services/surfaceflinger/Scheduler/EventThread.cpp b/services/surfaceflinger/Scheduler/EventThread.cpp
index fa2b0a6..a75235c 100644
--- a/services/surfaceflinger/Scheduler/EventThread.cpp
+++ b/services/surfaceflinger/Scheduler/EventThread.cpp
@@ -181,7 +181,7 @@
     event.header.timestamp = systemTime();
     event.hotplug.connected = connected;
 
-    mPendingEvents.add(event);
+    mPendingEvents.push(event);
     mCondition.notify_all();
 }
 
@@ -244,11 +244,11 @@
 
         if (!timestamp) {
             // no vsync event, see if there are some other event
-            eventPending = !mPendingEvents.isEmpty();
+            eventPending = !mPendingEvents.empty();
             if (eventPending) {
                 // we have some other event to dispatch
-                *outEvent = mPendingEvents[0];
-                mPendingEvents.removeAt(0);
+                *outEvent = mPendingEvents.front();
+                mPendingEvents.pop();
             }
         }
 
@@ -384,6 +384,7 @@
         result.appendFormat("    %p: count=%d\n", connection.get(),
                             connection != nullptr ? connection->count : 0);
     }
+    result.appendFormat("  other-events-pending: %zu\n", mPendingEvents.size());
 }
 
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