Fixed chat send history functionality in Firefox and Edge (#1956)

* Fixed chat send history functionality  on Firefox and Edge

* Updated CHANGELOG.md

CHANGELOG.md

@@ -40,6 +40,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fix [#1943](https://github.com/Microsoft/BotFramework-WebChat/issues/1943). Fix extra vertical padding in IE11 and Firefox, by [@compulim](https://github.com/compulim) in PR [#1949](https://github.com/Microsoft/BotFramework-WebChat/pull/1949)
 - Fix [#1945](https://github.com/Microsoft/BotFramework-WebChat/issues/1945). QA fixes for 4.4, by [@corinagum](https://github.com/johndoe) in PR [#1950](https://github.com/Microsoft/BotFramework-WebChat/pull/1950)
 - Fix [#1947](https://github.com/Microsoft/BotFramework-WebChat/issues/1947). Fix scrollbar in suggested action should be hidden in Firefox, remove gaps, and use style set for customizing `react-film`, by [@compulim](https://github.com/compulim) in PR [#1953](https://github.com/Microsoft/BotFramework-WebChat/pull/1953)
+- Fix [#1948](https://github.com/Microsoft/BotFramework-WebChat/issues/1948). Fixed sample 17.chat-send-history to work with Firefox and Edge, by [@tdurnford](https://github.com/tdurnford) in PR [#1956](https://github.com/Microsoft/BotFramework-WebChat/pull/1956)
 
 ### Changed
 - Deployment: Bumps to [`[email protected]`](https://github.com/azure/blobxfer/), by [@compulim](https://github.com/compulim), in PR [#1897](https://github.com/Microsoft/BotFramework-WebChat/pull/1897)

samples/17.chat-send-history/src/App.js

@@ -42,9 +42,7 @@ export default class App extends React.Component {
 
       switch (e.key) {
         case 'ArrowUp':
-          if (target.selectionStart === 0) {
-            text = this.history.getNext();
-          }
+          text = this.history.getNext();
           break;
         case 'ArrowDown':
             text = this.history.getPrevious();