Create EGLImages during buffer allocation

EGLImage creation is now performed on an async binder thread, so now GPU
composition should rarely be stalled by expensive image creation.

Bug: 129008989
Test: systrace
Change-Id: I9732f866933a8950a4c69ff51d5ac1622bbb3470
diff --git a/libs/gui/include/gui/ConsumerBase.h b/libs/gui/include/gui/ConsumerBase.h
index 366ced3..7c26482 100644
--- a/libs/gui/include/gui/ConsumerBase.h
+++ b/libs/gui/include/gui/ConsumerBase.h
@@ -141,6 +141,7 @@
     // classes if they want the notification.
     virtual void onFrameAvailable(const BufferItem& item) override;
     virtual void onFrameReplaced(const BufferItem& item) override;
+    virtual void onBufferAllocated(const BufferItem& item) override;
     virtual void onBuffersReleased() override;
     virtual void onSidebandStreamChanged() override;