Bug 1580362 - Rewinding while recording should rewind to the last breakpoint. r=bhackett

Differential Revision: https://phabricator.services.mozilla.com/D45473

--HG--
extra : moz-landing-system : lando

devtools/client/webreplay/components/WebReplayPlayer.js

@@ -425,14 +425,6 @@ class WebReplayPlayer extends Component {
   }
 
   async rewind() {
-    if (this.isRecording()) {
-      await this.threadFront.interrupt();
-    }
-
-    if (!this.isPaused()) {
-      return null;
-    }
-
     return this.threadFront.rewind();
   }
 

devtools/shared/fronts/thread.js

@@ -125,7 +125,12 @@ class ThreadFront extends FrontClassWithSpec(threadSpec) {
   /**
    * Rewind a thread until a breakpoint is hit.
    */
-  rewind() {
+  async rewind() {
+    if (!this.paused) {
+      this.interrupt();
+      await this.once("paused");
+    }
+
     this._doResume(null, true);
   }