Flag: Trunk-stable flag for migrating pacesetter to display with highest refresh rate

PDARR is comprised of three main changes:
1. "Greedy" follower display presentation via follower display backpressure
2. Migration of pacesetter display to the highest refresh rate display
3. Proper buffer release/transaction callback if a buffer is used across multiple displays

This CL introduces a flag for #2, pacesetter display migration

Refer to go/pdarr-1pager for details.

Flag: com.android.graphics.surfaceflinger.flags.pacesetter_selection
Bug: 374072507
Test: N/A
Change-Id: I4417c415bd20c2c09ed1c5f3cf75b8d0e5e522ec

Author: Su Hong Koo

services/surfaceflinger/common/FlagManager.cpp

@@ -168,6 +168,7 @@ void FlagManager::dump(std::string& result) const {
     DUMP_ACONFIG_FLAG(misc1);
     DUMP_ACONFIG_FLAG(no_vsyncs_on_screen_off);
     DUMP_ACONFIG_FLAG(override_trusted_overlay);
+    DUMP_ACONFIG_FLAG(pacesetter_selection);
     DUMP_ACONFIG_FLAG(protected_if_client);
     DUMP_ACONFIG_FLAG(reject_dupe_layerstacks);
     DUMP_ACONFIG_FLAG(renderable_buffer_usage);
@@ -274,6 +275,7 @@ FLAG_MANAGER_ACONFIG_FLAG(renderable_buffer_usage, "")
 FLAG_MANAGER_ACONFIG_FLAG(restore_blur_step, "debug.renderengine.restore_blur_step")
 FLAG_MANAGER_ACONFIG_FLAG(dont_skip_on_early_ro, "")
 FLAG_MANAGER_ACONFIG_FLAG(no_vsyncs_on_screen_off, "debug.sf.no_vsyncs_on_screen_off")
+FLAG_MANAGER_ACONFIG_FLAG(pacesetter_selection, "debug.sf.pacesetter_selection")
 FLAG_MANAGER_ACONFIG_FLAG(protected_if_client, "")
 FLAG_MANAGER_ACONFIG_FLAG(graphite_renderengine, "debug.renderengine.graphite")
 FLAG_MANAGER_ACONFIG_FLAG(filter_frames_before_trace_starts, "")

services/surfaceflinger/common/include/common/FlagManager.h

@@ -97,12 +97,14 @@ class FlagManager {
     bool graphite_renderengine() const;
     bool hdcp_level_hal() const;
     bool hdcp_negotiation() const;
+    bool idle_screen_refresh_rate_timeout() const;
     bool latch_unsignaled_with_auto_refresh_changed() const;
     bool local_tonemap_screenshots() const;
     bool luts_api() const;
     bool misc1() const;
     bool no_vsyncs_on_screen_off() const;
     bool override_trusted_overlay() const;
+    bool pacesetter_selection() const;
     bool protected_if_client() const;
     bool reject_dupe_layerstacks() const;
     bool renderable_buffer_usage() const;

services/surfaceflinger/surfaceflinger_flags_new.aconfig

@@ -250,6 +250,13 @@ flag {
   is_fixed_read_only: true
 } # no_vsyncs_on_screen_off
 
+flag {
+  name: "pacesetter_selection"
+  namespace: "desktop_display"
+  description: "Moves pacesetter designation to the display with highest refresh rate. Prefers to keep the same display as pacesetter if there are multiple displays of the same highest refresh rate."
+  bug: "374072507"
+} # pacesetter_selection
+
 flag {
   name: "reject_dupe_layerstacks"
   namespace: "window_surfaces"