Remove USE_HWC2 usage

It's always true now

Test: didn't
Change-Id: Ibefde5feaeaec8fb68cbc6ea1c019bf8b5e608bb
diff --git a/libs/hwui/Android.bp b/libs/hwui/Android.bp
index fb82744..6533eb9 100644
--- a/libs/hwui/Android.bp
+++ b/libs/hwui/Android.bp
@@ -45,9 +45,6 @@
     ],
 
     product_variables: {
-        device_uses_hwc2: {
-            cflags: ["-DUSE_HWC2"],
-        },
         eng: {
             lto: {
                 never: true,
diff --git a/libs/hwui/JankTracker.cpp b/libs/hwui/JankTracker.cpp
index f2d50cd..39ed9a0 100644
--- a/libs/hwui/JankTracker.cpp
+++ b/libs/hwui/JankTracker.cpp
@@ -81,7 +81,6 @@
 JankTracker::JankTracker(ProfileDataContainer* globalData, const DisplayInfo& displayInfo) {
     mGlobalData = globalData;
     nsecs_t frameIntervalNanos = static_cast<nsecs_t>(1_s / displayInfo.fps);
-#if USE_HWC2
     nsecs_t sfOffset = frameIntervalNanos - (displayInfo.presentationDeadline - 1_ms);
     nsecs_t offsetDelta = sfOffset - displayInfo.appVsyncOffset;
     // There are two different offset cases. If the offsetDelta is positive
@@ -95,7 +94,6 @@
         // return due to the staggering of VSYNC-app & VSYNC-sf.
         mDequeueTimeForgiveness = offsetDelta + 4_ms;
     }
-#endif
     setFrameInterval(frameIntervalNanos);
 }