Reland "DevTools: allow showing views above and below the Sources sidebar."

This reverts commit 41f9647f.

Reason for revert: applying fix.

Original change's description:
> Revert "DevTools: allow showing views above and below the Sources sidebar."
>
> This reverts commit d21d2ed3.
>
> Reason for revert: Causing devtools_eslint failure
> https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8928389307771200912/+/steps/devtools_eslint/0/stdout
>
> Original change's description:
> > DevTools: allow showing views above and below the Sources sidebar.
> >
> > Change-Id: I76a8edbc45bd6e2d775b48c8f93e288d82bed817
> > Reviewed-on: https://chromium-review.googlesource.com/c/1357513
> > Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
> > Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#612830}
>
> TBR=dgozman@chromium.org,pfeldman@chromium.org,kozy@chromium.org
>
> # Not skipping CQ checks because original CL landed > 1 day ago.
>
> Change-Id: I58fd8fab81766fee2aca0747a78f4ac61647f7cf
> Reviewed-on: https://chromium-review.googlesource.com/c/1358118
> Reviewed-by: calamity <calamity@chromium.org>
> Commit-Queue: calamity <calamity@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#613013}

TBR=dgozman@chromium.org

Change-Id: I0e4cd1fe9585f7ccd365cc449ca0429e0b031141
Reviewed-on: https://chromium-review.googlesource.com/c/1358045
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613020}

third_party/blink/renderer/devtools/front_end/browser_debugger/module.json

@@ -2,7 +2,7 @@
     "extensions": [
         {
             "type": "view",
-            "location": "sources-sidebar",
+            "location": "sources.sidebar-bottom",
             "id": "sources.eventListenerBreakpoints",
             "title": "Event Listener Breakpoints",
             "order": 9,
@@ -18,7 +18,7 @@
         },
         {
             "type": "view",
-            "location": "sources-sidebar",
+            "location": "sources.sidebar-bottom",
             "id": "sources.xhrBreakpoints",
             "title": "XHR/fetch Breakpoints",
             "order": 5,
@@ -28,7 +28,7 @@
         },
         {
             "type": "view",
-            "location": "sources-sidebar",
+            "location": "sources.sidebar-bottom",
             "id": "sources.domBreakpoints",
             "title": "DOM Breakpoints",
             "order": 7,
@@ -67,7 +67,7 @@
         },
         {
             "type": "view",
-            "location": "sources-sidebar",
+            "location": "sources.sidebar-bottom",
             "id": "sources.globalListeners",
             "title": "Global Listeners",
             "order": 8,

third_party/blink/renderer/devtools/front_end/sources/SourcesPanel.js

@@ -251,7 +251,8 @@ Sources.SourcesPanel = class extends UI.Panel {
    * @return {?UI.ViewLocation}
    */
   resolveLocation(locationName) {
-    if (locationName === 'sources-sidebar')
+    if (locationName === 'sources.sidebar-top' || locationName === 'sources.sidebar-bottom' ||
+        locationName === 'sources.sidebar-tabs')
       return this._sidebarPaneStack;
     else
       return this._navigatorTabbedLocation;
@@ -899,6 +900,7 @@ Sources.SourcesPanel = class extends UI.Panel {
     this._sidebarPaneStack.widget().element.classList.add('overflow-auto');
     this._sidebarPaneStack.widget().show(vbox.element);
     this._sidebarPaneStack.widget().element.appendChild(this._debuggerPausedMessage.element());
+    this._sidebarPaneStack.appendApplicableItems('sources.sidebar-top');
     vbox.element.appendChild(this._debugToolbar.element);
 
     if (this._threadsSidebarPane)
@@ -937,11 +939,12 @@ Sources.SourcesPanel = class extends UI.Panel {
       this._splitWidget.installResizer(this._debugToolbar.gripElementForResize());
       tabbedLocation.appendView(scopeChainView);
       tabbedLocation.appendView(this._watchSidebarPane);
+      tabbedLocation.appendApplicableItems('sources.sidebar-tabs');
       this._extensionSidebarPanesContainer = tabbedLocation;
       this.sidebarPaneView = splitWidget;
     }
 
-    this._sidebarPaneStack.appendApplicableItems('sources-sidebar');
+    this._sidebarPaneStack.appendApplicableItems('sources.sidebar-bottom');
     const extensionSidebarPanes = Extensions.extensionServer.sidebarPanes();
     for (let i = 0; i < extensionSidebarPanes.length; ++i)
       this._addExtensionSidebarPane(extensionSidebarPanes[i]);

third_party/blink/renderer/devtools/front_end/sources/module.json

@@ -715,11 +715,24 @@
         {
             "type": "@UI.ViewLocationResolver",
             "name": "navigator-view",
+            "category": "Sources",
+            "className": "Sources.SourcesPanel"
+        },
+        {
+            "type": "@UI.ViewLocationResolver",
+            "name": "sources.sidebar-top",
+            "category": "Sources",
+            "className": "Sources.SourcesPanel"
+        },
+        {
+            "type": "@UI.ViewLocationResolver",
+            "name": "sources.sidebar-bottom",
+            "category": "Sources",
             "className": "Sources.SourcesPanel"
         },
         {
             "type": "@UI.ViewLocationResolver",
-            "name": "sources-sidebar",
+            "name": "sources.sidebar-tabs",
             "category": "Sources",
             "className": "Sources.SourcesPanel"
         },