[AChoreographer] Add refresh rate callback.

This will augment the NDK to respond to display events where the display
refresh rate changes. Consumers of this api will include:
* HWUI, for implementing a policy for determining whether to use
render-ahead,
* Swappy, to potentially replace jumping into Java from native code to
respond to display evnets there.
* Any other native app that would rely on the up-to-date display refresh
rate.

Currently however this is not yet exposed to NDK as CTS is not yet
written. Once CTS is written then this will be formally exposed to NDK.
For now we'll leave these as APEX apis to represent incremental
progress.

Bug: 136262896
Test: builds
Change-Id: I66d393f93eb5d681547411e330ef1b8950a35c5d

1 files changed, 8 insertions, 0 deletions

diff --git a/libs/gui/DisplayEventReceiver.cpp b/libs/gui/DisplayEventReceiver.cpp
index b8faa2df4c..fd6aaf8b46 100644
--- a/libs/gui/DisplayEventReceiver.cpp
+++ b/libs/gui/DisplayEventReceiver.cpp
@@ -79,6 +79,14 @@ status_t DisplayEventReceiver::requestNextVsync() {
     return NO_INIT;
 }
 
+status_t DisplayEventReceiver::toggleConfigEvents(
+        ISurfaceComposer::ConfigChanged configChangeFlag) {
+    if (mEventConnection != nullptr) {
+        mEventConnection->toggleConfigEvents(configChangeFlag);
+        return NO_ERROR;
+    }
+    return NO_INIT;
+}
 
 ssize_t DisplayEventReceiver::getEvents(DisplayEventReceiver::Event* events,
         size_t count) {