[DevTools] Add preferred size to WebInspector.View.

Source/devtools/front_end/SourcesPanel.js

Index: Source/devtools/front_end/SourcesPanel.js
diff --git a/Source/devtools/front_end/SourcesPanel.js b/Source/devtools/front_end/SourcesPanel.js
index e617973d7bc8b7143647d1f6f423ba6e747f9ccc..4528c0dc5a2ff0e659b64872a228a41b81abff34 100644
--- a/Source/devtools/front_end/SourcesPanel.js
+++ b/Source/devtools/front_end/SourcesPanel.js
@@ -996,7 +996,7 @@ WebInspector.SourcesPanel.prototype = {
         vbox.element.appendChild(this._debugToolbarDrawer);
         vbox.element.appendChild(this.debugToolbar);
         vbox.element.appendChild(this.threadsToolbar.element);
-        vbox.setMinimumSize(WebInspector.SourcesPanel.minToolbarWidth, 25);
+        vbox.setMinimumSize(25, 25, WebInspector.SourcesPanel.minToolbarWidth, 100);
         var sidebarPaneStack = new WebInspector.SidebarPaneStack();
         sidebarPaneStack.element.classList.add("flex-auto");
         sidebarPaneStack.show(vbox.element);