Bug 1980240 - Refactor tabs drag and drop code into its own module r=tabbrowser-reviewers,sthompson

Differential Revision: https://phabricator.services.mozilla.com/D263022

Author: nikk15

browser/base/content/browser-main.js

@@ -21,6 +21,7 @@
   Services.scriptloader.loadSubScript("chrome://browser/content/sidebar/browser-sidebar.js", this);
   Services.scriptloader.loadSubScript("chrome://browser/content/browser-customtitlebar.js", this);
   Services.scriptloader.loadSubScript("chrome://browser/content/browser-unified-extensions.js", this);
+  Services.scriptloader.loadSubScript("chrome://browser/content/tabbrowser/drag-and-drop.js", this);
   Services.scriptloader.loadSubScript("chrome://browser/content/tabbrowser/tab.js", this);
   Services.scriptloader.loadSubScript("chrome://browser/content/tabbrowser/tabbrowser.js", this);
   Services.scriptloader.loadSubScript("chrome://browser/content/tabbrowser/tabgroup.js", this);

browser/base/content/test/performance/browser_tabdetach.js

@@ -12,8 +12,9 @@
 const EXPECTED_REFLOWS = [
   {
     stack: [
-      "clientPos@chrome://browser/content/tabbrowser/tabs.js",
-      "startTabDrag@chrome://browser/content/tabbrowser/tabs.js",
+      "clientPos@chrome://browser/content/tabbrowser/drag-and-drop.js",
+      "startTabDrag@chrome://browser/content/tabbrowser/drag-and-drop.js",
+      "handle_dragstart@chrome://browser/content/tabbrowser/drag-and-drop.js",
       "on_dragstart@chrome://browser/content/tabbrowser/tabs.js",
       "handleEvent@chrome://browser/content/tabbrowser/tabs.js",
       "synthesizeMouseAtPoint@chrome://mochikit/content/tests/SimpleTest/EventUtils.js",
@@ -26,7 +27,8 @@ const EXPECTED_REFLOWS = [
   {
     stack: [
       "get scrollPosition@chrome://global/content/elements/arrowscrollbox.js",
-      "startTabDrag@chrome://browser/content/tabbrowser/tabs.js",
+      "startTabDrag@chrome://browser/content/tabbrowser/drag-and-drop.js",
+      "handle_dragstart@chrome://browser/content/tabbrowser/drag-and-drop.js",
       "on_dragstart@chrome://browser/content/tabbrowser/tabs.js",
       "handleEvent@chrome://browser/content/tabbrowser/tabs.js",
       "synthesizeMouseAtPoint@chrome://mochikit/content/tests/SimpleTest/EventUtils.js",
@@ -36,8 +38,9 @@ const EXPECTED_REFLOWS = [
   },
   {
     stack: [
-      "#updateTabStylesOnDrag@chrome://browser/content/tabbrowser/tabs.js",
-      "startTabDrag@chrome://browser/content/tabbrowser/tabs.js",
+      "#updateTabStylesOnDrag@chrome://browser/content/tabbrowser/drag-and-drop.js",
+      "startTabDrag@chrome://browser/content/tabbrowser/drag-and-drop.js",
+      "handle_dragstart@chrome://browser/content/tabbrowser/drag-and-drop.js",
       "on_dragstart@chrome://browser/content/tabbrowser/tabs.js",
       "handleEvent@chrome://browser/content/tabbrowser/tabs.js",
       "synthesizeMouseAtPoint@chrome://mochikit/content/tests/SimpleTest/EventUtils.js",

browser/components/tabbrowser/TabsList.sys.mjs

@@ -706,9 +706,13 @@ export class TabsPanel extends TabsListBase {
         ? getTabGroupFromRow(row).labelElement
         : getTabFromRow(row);
 
-    this.gBrowser.tabContainer.startTabDrag(event, elementToDrag, {
-      fromTabList: true,
-    });
+    this.gBrowser.tabContainer.tabDragAndDrop.startTabDrag(
+      event,
+      elementToDrag,
+      {
+        fromTabList: true,
+      }
+    );
   }
 
   /**
@@ -724,7 +728,8 @@ export class TabsPanel extends TabsListBase {
    * @returns {boolean}
    */
   _isMovingTabs(event) {
-    var effects = this.gBrowser.tabContainer.getDropEffectForTabDrag(event);
+    var effects =
+      this.gBrowser.tabContainer.tabDragAndDrop.getDropEffectForTabDrag(event);
     return effects == "move";
   }