Camera2: Add onCaptureQueueEmpty callback

onCaptureQueueEmpty is called when the non-repeating request queue in
cameraservice becomes empty. Application can use this callback as a
trigger for a new request.

Test: testMultipleCapture in PerformanceTest.java

Bug: 29006447
Change-Id: Id21afd74381e0b70f924c6026025c91a8ffd5ee0
diff --git a/services/camera/libcameraservice/common/Camera2ClientBase.cpp b/services/camera/libcameraservice/common/Camera2ClientBase.cpp
index ccd1e4d..7e26153 100644
--- a/services/camera/libcameraservice/common/Camera2ClientBase.cpp
+++ b/services/camera/libcameraservice/common/Camera2ClientBase.cpp
@@ -307,6 +307,12 @@
 }
 
 template <typename TClientBase>
+void Camera2ClientBase<TClientBase>::notifyRequestQueueEmpty() {
+
+    ALOGV("%s: Request queue now empty", __FUNCTION__);
+}
+
+template <typename TClientBase>
 void Camera2ClientBase<TClientBase>::notifyRepeatingRequestError(long lastFrameNumber) {
     (void)lastFrameNumber;
 
diff --git a/services/camera/libcameraservice/common/Camera2ClientBase.h b/services/camera/libcameraservice/common/Camera2ClientBase.h
index dbbf638..9fd0a78 100644
--- a/services/camera/libcameraservice/common/Camera2ClientBase.h
+++ b/services/camera/libcameraservice/common/Camera2ClientBase.h
@@ -73,6 +73,7 @@
     virtual void          notifyAutoWhitebalance(uint8_t newState,
                                                  int triggerId);
     virtual void          notifyPrepared(int streamId);
+    virtual void          notifyRequestQueueEmpty();
     virtual void          notifyRepeatingRequestError(long lastFrameNumber);
 
     int                   getCameraId() const;
diff --git a/services/camera/libcameraservice/common/CameraDeviceBase.h b/services/camera/libcameraservice/common/CameraDeviceBase.h
index 984d84b..f30afe3 100644
--- a/services/camera/libcameraservice/common/CameraDeviceBase.h
+++ b/services/camera/libcameraservice/common/CameraDeviceBase.h
@@ -204,6 +204,7 @@
         virtual void notifyShutter(const CaptureResultExtras &resultExtras,
                 nsecs_t timestamp) = 0;
         virtual void notifyPrepared(int streamId) = 0;
+        virtual void notifyRequestQueueEmpty() = 0;
 
         // Required only for API1
         virtual void notifyAutoFocus(uint8_t newState, int triggerId) = 0;