[sync master] 1.3.15.5

- 外部Chrome拡張連携への予告

![tumblr_ncuv5aiajp1qd1ozgo1_500](https://cloud.githubusercontent.com/assets/931554/4701549/3c218a2a-585a-11e4-9b28-67e420621c0e.gif)

![infhaku](https://cloud.githubusercontent.com/assets/931554/4701543/349f4a44-585a-11e4-9259-15d419d57b07.gif)

![tumblr_ncvcj0gqnh1qzcd3bo1_400](https://cloud.githubusercontent.com/assets/931554/4701555/4a1ddbb0-585a-11e4-8324-ac46fe1df5f3.gif)