DevTools: use diff_match_patch instead of jsdifflib for text diffing.

Source/devtools/devtools.gypi

 #
 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #         * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #         * Redistributions in binary form must reproduce the above
@@ skipping 382 matching lines @@
             'front_end/console/consoleView.css',
             'front_end/console/ConsolePanel.js',
             'front_end/console/ConsoleView.js',
             'front_end/console/ConsoleViewMessage.js',
         ],
         'devtools_devices_js_files': [
             'front_end/devices/devicesView.css',
             'front_end/devices/DevicesDialog.js',
             'front_end/devices/DevicesView.js',
         ],
+        'devtools_diff_js_files': [
+            'front_end/diff/Diff.js',
+            'front_end/diff/diff_match_patch.js',
+        ],
         'devtools_elements_js_files': [
             'front_end/elements/bezierEditor.css',
             'front_end/elements/breadcrumbs.css',
             'front_end/elements/computedStyleSidebarPane.css',
             'front_end/elements/elementsPanel.css',
             'front_end/elements/elementsTreeOutline.css',
             'front_end/elements/spectrum.css',
             'front_end/elements/BezierEditor.js',
             'front_end/elements/BezierUI.js',
             'front_end/elements/ElementsBreadcrumbs.js',
@@ skipping 186 matching lines @@
             'front_end/sources/CSSSourceFrame.js',
             'front_end/sources/EditingLocationHistoryManager.js',
             'front_end/sources/EventListenerBreakpointsSidebarPane.js',
             'front_end/sources/FileBasedSearchResultsPane.js',
             'front_end/sources/FilePathScoreFunction.js',
             'front_end/sources/FilteredItemSelectionDialog.js',
             'front_end/sources/InplaceFormatterEditorAction.js',
             'front_end/sources/JavaScriptBreakpointsSidebarPane.js',
             'front_end/sources/JavaScriptCompiler.js',
             'front_end/sources/JavaScriptSourceFrame.js',
-            'front_end/sources/jsdifflib.js',
             'front_end/sources/NavigatorView.js',
             'front_end/sources/ObjectEventListenersSidebarPane.js',
             'front_end/sources/RevisionHistoryView.js',
             'front_end/sources/ScopeChainSidebarPane.js',
             'front_end/sources/ScriptFormatter.js',
             'front_end/sources/ScriptFormatterEditorAction.js',
             'front_end/sources/ServiceWorkersSidebarPane.js',
             'front_end/sources/SimpleHistoryManager.js',
             'front_end/sources/SourcesNavigator.js',
             'front_end/sources/SourcesPanel.js',
@@ skipping 81 matching lines @@
         ],
 
         'devtools_modules_js_files': [
             '<@(devtools_accessibility_js_files)',
             '<@(devtools_animation_js_files)',
             '<@(devtools_audits_js_files)',
             '<@(devtools_cm_modes_js_files)',
             '<@(devtools_components_lazy_js_files)',
             '<@(devtools_console_js_files)',
             '<@(devtools_devices_js_files)',
+            '<@(devtools_diff_js_files)',
             '<@(devtools_elements_js_files)',
             '<@(devtools_emulated_devices_js_files)',
             '<@(devtools_extensions_js_files)',
             '<@(devtools_heap_snapshot_worker_js_files)',
             '<@(devtools_layers_js_files)',
             '<@(devtools_network_js_files)',
             '<@(devtools_profiler_js_files)',
             '<@(devtools_promises_js_files)',
             '<@(devtools_resources_js_files)',
             '<@(devtools_security_js_files)',
@@ skipping 83 matching lines @@
             'front_end/Images/toolbarItemSelected.png',
             'front_end/Images/touchCursor.png',
             'front_end/Images/touchCursor_2x.png',
             'front_end/Images/updateServiceWorker.svg',
         ],
         'devtools_extension_api_files': [
             'front_end/extensions/ExtensionAPI.js',
         ],
     },
 }