Camera: Enable Histogram feature.

Link the histogram enable/disable commands from
application to the HAL layer.

Change-Id: I7803da586a85720a8ec9ca98d61f6d67d75f40d5
diff --git a/services/camera/libcameraservice/api1/CameraClient.cpp b/services/camera/libcameraservice/api1/CameraClient.cpp
index 109b7eb..77eb656 100644
--- a/services/camera/libcameraservice/api1/CameraClient.cpp
+++ b/services/camera/libcameraservice/api1/CameraClient.cpp
@@ -676,6 +676,12 @@
     } else if (cmd == CAMERA_CMD_PING) {
         // If mHardware is 0, checkPidAndHardware will return error.
         return OK;
+#ifdef QCOM_HARDWARE
+    } else if (cmd == CAMERA_CMD_HISTOGRAM_ON) {
+        enableMsgType(CAMERA_MSG_STATS_DATA);
+    } else if (cmd == CAMERA_CMD_HISTOGRAM_OFF) {
+        disableMsgType(CAMERA_MSG_STATS_DATA);
+#endif
     }
 
     return mHardware->sendCommand(cmd, arg1, arg2);