MD History/Downloads: convert .bind(this) and function property values to use =>

chrome/browser/resources/md_history/synced_device_card.js

Index: chrome/browser/resources/md_history/synced_device_card.js
diff --git a/chrome/browser/resources/md_history/synced_device_card.js b/chrome/browser/resources/md_history/synced_device_card.js
index 91a41d3b49aefc35460bbad9e2116ebe945f9619..2ee923c68508c521a36b50a33ca025b0aec40aec 100644
--- a/chrome/browser/resources/md_history/synced_device_card.js
+++ b/chrome/browser/resources/md_history/synced_device_card.js
@@ -18,7 +18,7 @@ Polymer({
      */
     tabs: {
       type: Array,
-      value: function() { return []; },
+      value: () => [],

[dpapad, 2016/12/21 23:49:53]

Can we use arrow only when:
 1) Used inside a member function.
 2) we previously we used bind()
 
for now? I am leaning towards considering non-bound functions more readable with
the old syntax.

[michaelpg, 2016/12/22 07:35:19]

why?
why?? (why limit it to that?)

[Dan Beam, 2016/12/22 18:33:17]

well, I obviously agreed with ... myself when I made this change, but my
understanding of what dpapad@ is saying is that: => shines most when we're able
to drop .bind(this).  nobody's arguing against that, afaik.

       observer: 'updateIcons_'
     },