diff --git a/include/gui/BufferQueueConsumer.h b/include/gui/BufferQueueConsumer.h
index 0f42613..cde302f 100644
--- a/include/gui/BufferQueueConsumer.h
+++ b/include/gui/BufferQueueConsumer.h
@@ -47,7 +47,7 @@
     // returned.  The presentation time is in nanoseconds, and the time base
     // is CLOCK_MONOTONIC.
     virtual status_t acquireBuffer(BufferItem* outBuffer,
-            nsecs_t expectedPresent);
+            nsecs_t expectedPresent, uint64_t maxFrameNumber = 0) override;
 
     // See IGraphicBufferConsumer::detachBuffer
     virtual status_t detachBuffer(int slot);
@@ -148,9 +148,6 @@
     // Retrieve the sideband buffer stream, if any.
     virtual sp<NativeHandle> getSidebandStream() const;
 
-    // See IGraphicBufferConsumer::setShadowQueueSize
-    virtual void setShadowQueueSize(size_t size);
-
     // dump our state in a String
     virtual void dump(String8& result, const char* prefix) const;
 
diff --git a/include/gui/BufferQueueCore.h b/include/gui/BufferQueueCore.h
index a22015c..d7686ec 100644
--- a/include/gui/BufferQueueCore.h
+++ b/include/gui/BufferQueueCore.h
@@ -275,12 +275,6 @@
     // buffer as the number of frames that have elapsed since it was last queued
     uint64_t mBufferAge;
 
-    // mConsumerHasShadowQueue determines if acquireBuffer should be more
-    // cautious about dropping buffers so that it always returns a buffer that
-    // is represented in the consumer's shadow queue.
-    bool mConsumerHasShadowQueue;
-    size_t mConsumerShadowQueueSize;
-
 }; // class BufferQueueCore
 
 } // namespace android
diff --git a/include/gui/ConsumerBase.h b/include/gui/ConsumerBase.h
index 5be3ffb..f46bf01 100644
--- a/include/gui/ConsumerBase.h
+++ b/include/gui/ConsumerBase.h
@@ -152,7 +152,8 @@
     // initialization that must take place the first time a buffer is assigned
     // to a slot.  If it is overridden the derived class's implementation must
     // call ConsumerBase::acquireBufferLocked.
-    virtual status_t acquireBufferLocked(BufferItem *item, nsecs_t presentWhen);
+    virtual status_t acquireBufferLocked(BufferItem *item, nsecs_t presentWhen,
+            uint64_t maxFrameNumber = 0);
 
     // releaseBufferLocked relinquishes control over a buffer, returning that
     // control to the BufferQueue.
diff --git a/include/gui/GLConsumer.h b/include/gui/GLConsumer.h
index 4912580..c35c7be 100644
--- a/include/gui/GLConsumer.h
+++ b/include/gui/GLConsumer.h
@@ -241,7 +241,8 @@
 
     // acquireBufferLocked overrides the ConsumerBase method to update the
     // mEglSlots array in addition to the ConsumerBase behavior.
-    virtual status_t acquireBufferLocked(BufferItem *item, nsecs_t presentWhen);
+    virtual status_t acquireBufferLocked(BufferItem *item, nsecs_t presentWhen,
+            uint64_t maxFrameNumber = 0) override;
 
     // releaseBufferLocked overrides the ConsumerBase method to update the
     // mEglSlots array in addition to the ConsumerBase.
diff --git a/include/gui/IGraphicBufferConsumer.h b/include/gui/IGraphicBufferConsumer.h
index 0be09a2..6363a3a 100644
--- a/include/gui/IGraphicBufferConsumer.h
+++ b/include/gui/IGraphicBufferConsumer.h
@@ -69,6 +69,12 @@
     // returned.  The presentation time is in nanoseconds, and the time base
     // is CLOCK_MONOTONIC.
     //
+    // If maxFrameNumber is non-zero, it indicates that acquireBuffer should
+    // only return a buffer with a frame number less than or equal to
+    // maxFrameNumber. If no such frame is available (such as when a buffer has
+    // been replaced but the consumer has not received the onFrameReplaced
+    // callback), then PRESENT_LATER will be returned.
+    //
     // Return of NO_ERROR means the operation completed as normal.
     //
     // Return of a positive value means the operation could not be completed
@@ -78,7 +84,8 @@
     //
     // Return of a negative value means an error has occurred:
     // * INVALID_OPERATION - too many buffers have been acquired
-    virtual status_t acquireBuffer(BufferItem* buffer, nsecs_t presentWhen) = 0;
+    virtual status_t acquireBuffer(BufferItem* buffer, nsecs_t presentWhen,
+            uint64_t maxFrameNumber = 0) = 0;
 
     // detachBuffer attempts to remove all ownership of the buffer in the given
     // slot from the buffer queue. If this call succeeds, the slot will be
@@ -248,11 +255,6 @@
     // Retrieve the sideband buffer stream, if any.
     virtual sp<NativeHandle> getSidebandStream() const = 0;
 
-    // setShadowQueueSize notifies the BufferQueue that the consumer is
-    // shadowing its queue and allows it to limit the number of buffers it is
-    // permitted to drop during acquire so as to not get out of sync.
-    virtual void setShadowQueueSize(size_t size) = 0;
-
     // dump state into a string
     virtual void dump(String8& result, const char* prefix) const = 0;