DevTools: bake generic css files into the concatenated one.

Source/devtools/devtools.gypi

Index: Source/devtools/devtools.gypi
diff --git a/Source/devtools/devtools.gypi b/Source/devtools/devtools.gypi
index a908521c6bfc9f0c0bd266686e214640aa5e916b..66eaaabe2f25f5aa153d8de594f70f41f6b5ef5f 100644
--- a/Source/devtools/devtools.gypi
+++ b/Source/devtools/devtools.gypi
@@ -51,9 +51,12 @@
             'front_end/TestController.js',
             'front_end/dialog.css',
             'front_end/inspector.css',
-            'front_end/tabbedPane.css',
             'front_end/inspectorSyntaxHighlight.css',
             'front_end/popover.css',
+            'front_end/sidebarPane.css',
+            'front_end/splitView.css',
+            'front_end/suggestBox.css',
+            'front_end/tabbedPane.css',
             '<@(devtools_main_js_files)',
             '<@(devtools_standalone_files)',
         ],
@@ -248,7 +251,6 @@
         'devtools_standalone_files': [
             'front_end/accelerometer.css',
             'front_end/auditsPanel.css',
-            'front_end/breadcrumbList.css',
             'front_end/breakpointsList.css',
             'front_end/cmdevtools.css',
             'front_end/dataGrid.css',
@@ -272,12 +274,9 @@
             'front_end/responsiveDesignView.css',
             'front_end/revisionHistory.css',
             'front_end/screencastView.css',
-            'front_end/sidebarPane.css',
             'front_end/sourcesPanel.css',
             'front_end/sourcesView.css',
             'front_end/spectrum.css',
-            'front_end/splitView.css',
-            'front_end/suggestBox.css',
             'front_end/timelinePanel.css',
             'front_end/canvasProfiler.css',
             'front_end/layersPanel.css',