SurfaceFlinger: Fix PTS on stale buffers

SurfaceFlinger's (Layer's) shadow copy of the BufferQueue queue was
getting out of sync for a few reasons. This change fixes these by
doing the following:

- Adds a check to re-synchronize the shadow copy every time we
  successfully acquire a buffer by first dropping stale buffers before
  removing the current buffer.
- Avoids trying to perform updates for buffers which have been rejected
  (for incorrect dimensions) by SurfaceFlinger.
- Adds IGraphicBufferConsumer::setShadowQueueSize, which allows the
  consumer to notify the BufferQueue that it is maintaining a shadow
  copy of the queue and prevents it from dropping so many buffers
  during acquireBuffer that it ends up returning a buffer for which the
  consumer has not yet received an onFrameAvailable call.

Bug: 20096136
Change-Id: I78d0738428005fc19b3be85cc8f1db498043612f
(cherry picked from commit 2e36f2283f48ab764b496490c73a132acf21df3a)
diff --git a/services/surfaceflinger/SurfaceFlingerConsumer.cpp b/services/surfaceflinger/SurfaceFlingerConsumer.cpp
index 19c497a..a9a2958 100644
--- a/services/surfaceflinger/SurfaceFlingerConsumer.cpp
+++ b/services/surfaceflinger/SurfaceFlingerConsumer.cpp
@@ -74,7 +74,7 @@
     int buf = item.mBuf;
     if (rejecter && rejecter->reject(mSlots[buf].mGraphicBuffer, item)) {
         releaseBufferLocked(buf, mSlots[buf].mGraphicBuffer, EGL_NO_SYNC_KHR);
-        return NO_ERROR;
+        return BUFFER_REJECTED;
     }
 
     // Release the previous buffer.
@@ -125,6 +125,10 @@
     return mConsumer->getSidebandStream();
 }
 
+void SurfaceFlingerConsumer::setShadowQueueSize(size_t size) {
+    mConsumer->setShadowQueueSize(size);
+}
+
 // We need to determine the time when a buffer acquired now will be
 // displayed.  This can be calculated:
 //   time when previous buffer's actual-present fence was signaled