BQ: Add and expose a unique id

Bug 29422927

Change-Id: I80eab94f073ebc378302f00fa86a740c3643657e
diff --git a/libs/gui/IGraphicBufferProducer.cpp b/libs/gui/IGraphicBufferProducer.cpp
index 2c48d83..7d7d09d 100644
--- a/libs/gui/IGraphicBufferProducer.cpp
+++ b/libs/gui/IGraphicBufferProducer.cpp
@@ -55,6 +55,7 @@
     SET_AUTO_REFRESH,
     SET_DEQUEUE_TIMEOUT,
     GET_LAST_QUEUED_BUFFER,
+    GET_UNIQUE_ID,
 };
 
 class BpGraphicBufferProducer : public BpInterface<IGraphicBufferProducer>
@@ -418,6 +419,25 @@
         *outFence = fence;
         return result;
     }
+
+    virtual status_t getUniqueId(uint64_t* outId) const {
+        Parcel data, reply;
+        data.writeInterfaceToken(IGraphicBufferProducer::getInterfaceDescriptor());
+        status_t result = remote()->transact(GET_UNIQUE_ID, data, &reply);
+        if (result != NO_ERROR) {
+            ALOGE("getUniqueId failed to transact: %d", result);
+        }
+        status_t actualResult = NO_ERROR;
+        result = reply.readInt32(&actualResult);
+        if (result != NO_ERROR) {
+            return result;
+        }
+        result = reply.readUint64(outId);
+        if (result != NO_ERROR) {
+            return result;
+        }
+        return actualResult;
+    }
 };
 
 // Out-of-line virtual method definition to trigger vtable emission in this
@@ -659,6 +679,20 @@
             }
             return NO_ERROR;
         }
+        case GET_UNIQUE_ID: {
+            CHECK_INTERFACE(IGraphicBufferProducer, data, reply);
+            uint64_t outId = 0;
+            status_t actualResult = getUniqueId(&outId);
+            status_t result = reply->writeInt32(actualResult);
+            if (result != NO_ERROR) {
+                return result;
+            }
+            result = reply->writeUint64(outId);
+            if (result != NO_ERROR) {
+                return result;
+            }
+            return NO_ERROR;
+        }
     }
     return BBinder::onTransact(code, data, reply, flags);
 }