Add icons for history-deleter (#327)

history-deleter/icons/LICENSE

@@ -0,0 +1 @@
+The history.svg” icon is taken from the Font Awesome iconset (http://fontawesome.io/icons/) and is used under the terms of its license: http://fontawesome.io/license/.

history-deleter/icons/history.svg

@@ -0,0 +1 @@
+<?xml version="1.0" ?><svg height="1792" viewBox="0 0 1792 1792" width="1792" xmlns="http://www.w3.org/2000/svg"><path d="M1664 896q0 156-61 298t-164 245-245 164-298 61q-172 0-327-72.5t-264-204.5q-7-10-6.5-22.5t8.5-20.5l137-138q10-9 25-9 16 2 23 12 73 95 179 147t225 52q104 0 198.5-40.5t163.5-109.5 109.5-163.5 40.5-198.5-40.5-198.5-109.5-163.5-163.5-109.5-198.5-40.5q-98 0-188 35.5t-160 101.5l137 138q31 30 14 69-17 40-59 40h-448q-26 0-45-19t-19-45v-448q0-42 40-59 39-17 69 14l130 129q107-101 244.5-156.5t284.5-55.5q156 0 298 61t245 164 164 245 61 298zm-640-288v448q0 14-9 23t-23 9h-320q-14 0-23-9t-9-23v-64q0-14 9-23t23-9h224v-352q0-14 9-23t23-9h64q14 0 23 9t9 23z"/></svg>

history-deleter/manifest.json

@@ -6,7 +6,12 @@
   "homepage_url": "https://github.com/mdn/webextensions-examples/tree/master/history-deleter",
   "page_action": {
     "default_title": "History deleter",
-    "default_popup": "history.html"
+    "default_popup": "history.html",
+    "default_icon": "icons/history.svg"
+  },
+  "icons": {
+    "48": "icons/history.svg",
+    "96": "icons/history.svg"
   },
   "permissions": [
     "activeTab",