Bug 1474224 - Use Photon "Open in New" icon for undock icon; r=jdescottes

As per https://design.firefox.com/icons/icons/android/open-in-new-24.svg
but rather adapted to match the proportions of the other icons and fit on
a 16x16 grid.

MozReview-Commit-ID: 9bGWiBjX1P4

--HG--
extra : rebase_source : 1b87badf8ed045368c7f3d003c3c4f4611ab6a4b

devtools/client/themes/images/dock-undock.svg

@@ -4,9 +4,8 @@
 <svg viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"
   fill="context-fill #0b0b0b">
   <path d="
-    M13 0a3 3 0 0 1 3 3v5a3 3 0 0 1-3 3h-5a3 3 0 0 1-3-3v-5a3 3 0 0 1 3-3z
-    M13 2h-5a1 1 0 0 0-1 1v5a1 1 0 0 0 1 1h5a1 1 0 0 0 1-1v-5a1 1 0 0 0-1-1z"/>
-  <path d="M9 13v-1h2v1a3 3 0 0 1-3 3
-    h-5a3 3 0 0 1-3-3v-5a3 3 0 0 1 3-3h1v2h-1a1 1 0 0 0-1 1v5
-    a1 1 0 0 0 1 1h5a1 1 0 0 0 1-1z"/>
+    M5 1a1 1 0 0 1 0 2h-2a1 1 0 0 0-1 1v8a1 1 0 0 0 1 1h10a1 1 0 0 0 1-1
+    a1 1 0 0 1 2 0a3 3 0 0 1-3 3h-10a3 3 0 0 1-3-3v-8a3 3 0 0 1 3-3z
+    M9 3a1 1 0 1 1 0-2h6a1 1 0 0 1 1 1v6a1 1 0 1 1-2 0v-3.586l-5.293 5.293
+    a1 1 0 0 1-1.414-1.414l5.293 -5.293z"/>
 </svg>