Revert "Add support for render-ahead"

This reverts commit ec100976e0655acaa204c8800dfb83dadae20cc8.

Reason for revert: b/77971494
Test: hwuiunit passes

Change-Id: I2e7dc719d2df1dd939b275496c0edc38e458c434
diff --git a/libs/hwui/renderthread/RenderProxy.h b/libs/hwui/renderthread/RenderProxy.h
index ca20755..433adeb 100644
--- a/libs/hwui/renderthread/RenderProxy.h
+++ b/libs/hwui/renderthread/RenderProxy.h
@@ -117,23 +117,7 @@
 
     ANDROID_API void addFrameMetricsObserver(FrameMetricsObserver* observer);
     ANDROID_API void removeFrameMetricsObserver(FrameMetricsObserver* observer);
-
-    /**
-     * Sets a render-ahead depth on the backing renderer. This will increase latency by
-     * <swapInterval> * renderAhead and increase memory usage by (3 + renderAhead) * <resolution>.
-     * In return the renderer will be less susceptible to jitter, resulting in a smoother animation.
-     *
-     * Not recommended to use in response to anything touch driven, but for canned animations
-     * where latency is not a concern careful use may be beneficial.
-     *
-     * Note that when increasing this there will be a frame gap of N frames where N is
-     * renderAhead - <current renderAhead>. When decreasing this if there are any pending
-     * frames they will retain their prior renderAhead value, so it will take a few frames
-     * for the decrease to flush through.
-     *
-     * @param renderAhead How far to render ahead, must be in the range [0..2]
-     */
-    ANDROID_API void setRenderAheadDepth(int renderAhead);
+    ANDROID_API long getDroppedFrameReportCount();
 
     ANDROID_API static int copySurfaceInto(sp<Surface>& surface, int left, int top, int right,
                                            int bottom, SkBitmap* bitmap);