Compare GraphicBuffers using handles.

This change fixes a bug in SurfaceTextureClient where GraphicBuffers
were being compared using pointer comparison rather than handles.

Change-Id: Ib8989af94be32d4efd86e020a732f5143088a863
diff --git a/libs/gui/SurfaceTextureClient.cpp b/libs/gui/SurfaceTextureClient.cpp
index 24cee24..0ed8be5 100644
--- a/libs/gui/SurfaceTextureClient.cpp
+++ b/libs/gui/SurfaceTextureClient.cpp
@@ -111,7 +111,7 @@
     LOGV("SurfaceTextureClient::cancelBuffer");
     Mutex::Autolock lock(mMutex);
     for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
-        if (mSlots[i].get() == buffer) {
+        if (mSlots[i]->handle == buffer->handle) {
             mSurfaceTexture->cancelBuffer(i);
             return OK;
         }
@@ -129,7 +129,7 @@
     LOGV("SurfaceTextureClient::queueBuffer");
     Mutex::Autolock lock(mMutex);
     for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
-        if (mSlots[i].get() == GraphicBuffer::getSelf(buffer)) {
+        if (mSlots[i]->handle == buffer->handle) {
             return mSurfaceTexture->queueBuffer(i);
         }
     }