libgui: Prepare for IGBC::BufferItem removal

Switches some dependencies from IGraphicBufferConsumer::BufferItem to
android::BufferItem and adds some methods to facilitate incrementally
changing client code to do the same.

Change-Id: I699ed0a6837076867ca756b28d1ffb2238f7a0d9
diff --git a/include/gui/BufferItemConsumer.h b/include/gui/BufferItemConsumer.h
index 45f329e..57e121e 100644
--- a/include/gui/BufferItemConsumer.h
+++ b/include/gui/BufferItemConsumer.h
@@ -76,8 +76,10 @@
     //
     // If waitForFence is true, and the acquired BufferItem has a valid fence object,
     // acquireBuffer will wait on the fence with no timeout before returning.
-    status_t acquireBuffer(BufferItem *item, nsecs_t presentWhen,
-        bool waitForFence = true);
+    status_t acquireBuffer(BufferQueue::BufferItem *item, nsecs_t presentWhen,
+            bool waitForFence = true);
+    status_t acquireBuffer(android::BufferItem* item, nsecs_t presentWhen,
+            bool waitForFence = true);
 
     // Returns an acquired buffer to the queue, allowing it to be reused. Since
     // only a fixed number of buffers may be acquired at a time, old buffers
diff --git a/include/gui/ConsumerBase.h b/include/gui/ConsumerBase.h
index f7ab5ac..46ad20e 100644
--- a/include/gui/ConsumerBase.h
+++ b/include/gui/ConsumerBase.h
@@ -153,8 +153,8 @@
     // 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(IGraphicBufferConsumer::BufferItem *item,
-        nsecs_t presentWhen);
+    virtual status_t acquireBufferLocked(BufferItem *item, nsecs_t presentWhen);
+    virtual status_t acquireBufferLocked(BufferQueue::BufferItem *item, nsecs_t presentWhen);
 
     // 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 bf9eb24..167ef20 100644
--- a/include/gui/GLConsumer.h
+++ b/include/gui/GLConsumer.h
@@ -241,8 +241,8 @@
 
     // acquireBufferLocked overrides the ConsumerBase method to update the
     // mEglSlots array in addition to the ConsumerBase behavior.
-    virtual status_t acquireBufferLocked(BufferQueue::BufferItem *item,
-        nsecs_t presentWhen);
+    virtual status_t acquireBufferLocked(BufferItem *item, nsecs_t presentWhen);
+    virtual status_t acquireBufferLocked(IGraphicBufferConsumer::BufferItem *item, nsecs_t presentWhen);
 
     // releaseBufferLocked overrides the ConsumerBase method to update the
     // mEglSlots array in addition to the ConsumerBase.