Remove obsolete debug option

This is dead code, stop maintaining it

Fixes: 159912967
Test: builds
Change-Id: Ia453eaf895554adbb2fa9c11c2bc8609e1037ea5
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index db6f1ad..edafaa5 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -398,10 +398,6 @@
     int debugDdms = atoi(value);
     ALOGI_IF(debugDdms, "DDMS debugging not supported");
 
-    property_get("debug.sf.disable_backpressure", value, "0");
-    mPropagateBackpressure = !atoi(value);
-    ALOGI_IF(!mPropagateBackpressure, "Disabling backpressure propagation");
-
     property_get("debug.sf.enable_gl_backpressure", value, "0");
     mPropagateBackpressureClientComposition = atoi(value);
     ALOGI_IF(mPropagateBackpressureClientComposition,
@@ -1841,10 +1837,7 @@
     // for the present fence to fire instead of just giving up on this frame to handle cases
     // where present fence is just about to get signaled.
     const int graceTimeForPresentFenceMs =
-            (mPropagateBackpressure &&
-             (mPropagateBackpressureClientComposition || !mHadClientComposition))
-            ? 1
-            : 0;
+            (mPropagateBackpressureClientComposition || !mHadClientComposition) ? 1 : 0;
 
     // Pending frames may trigger backpressure propagation.
     const TracedOrdinal<bool> framePending = {"PrevFramePending",
@@ -1903,7 +1896,7 @@
         ON_MAIN_THREAD(setActiveConfigInternal());
     }
 
-    if (framePending && mPropagateBackpressure) {
+    if (framePending) {
         if ((hwcFrameMissed && !gpuFrameMissed) || mPropagateBackpressureClientComposition) {
             signalLayerUpdate();
             return;