[DevTools] Extract platform module.

Source/devtools/devtools.gypi

Index: Source/devtools/devtools.gypi
diff --git a/Source/devtools/devtools.gypi b/Source/devtools/devtools.gypi
index dc42738178d1ca4c06584b86a4c9a46c312abcb4..a1d8ea0f1fdafb943767f1ef6acbe97cd5c1f575 100644
--- a/Source/devtools/devtools.gypi
+++ b/Source/devtools/devtools.gypi
@@ -41,6 +41,7 @@
             '<@(devtools_core_base_files)',
             '<@(devtools_host_js_files)',
             '<@(devtools_main_js_files)',
+            '<@(devtools_platform_js_files)',
             '<@(devtools_screencast_js_files)',
             '<@(devtools_sdk_js_files)',
             '<@(devtools_toolbox_bootstrap_js_files)',
@@ -87,7 +88,6 @@
             'front_end/common/TextUtils.js',
             'front_end/common/Throttler.js',
             'front_end/common/UIString.js',
-            'front_end/common/utilities.js',
             'front_end/common/WebInspector.js',
         ],
         'devtools_components_js_files': [
@@ -122,10 +122,8 @@
             'front_end/components/TimelineGrid.js',
         ],
         'devtools_host_js_files': [
-            'front_end/host/DOMExtension.js',
             'front_end/host/InspectorFrontendHost.js',
             'front_end/host/Platform.js',
-            'front_end/host/ToolboxHost.js',
             'front_end/host/UserMetrics.js',
         ],
         'devtools_screencast_js_files': [
@@ -206,6 +204,11 @@
             'front_end/bindings/TempFile.js',
             'front_end/bindings/WorkspaceController.js',
         ],
+        'devtools_platform_js_files': [
+            'front_end/platform/DOMExtension.js',
+            'front_end/platform/Promise.js',
+            'front_end/platform/utilities.js',
+        ],
         'devtools_toolbox_bootstrap_js_files': [
             'front_end/toolbox_bootstrap/Toolbox.js',
         ],
@@ -374,13 +377,14 @@
         'devtools_heap_snapshot_worker_js_files': [
             'front_end/common/TextUtils.js',
             'front_end/common/UIString.js',
-            'front_end/common/utilities.js',
             'front_end/heap_snapshot_worker/AllocationProfile.js',
             'front_end/heap_snapshot_worker/HeapSnapshot.js',
             'front_end/heap_snapshot_worker/HeapSnapshotLoader.js',
             'front_end/heap_snapshot_worker/HeapSnapshotWorker.js',
             'front_end/heap_snapshot_worker/HeapSnapshotWorkerDispatcher.js',
             'front_end/heap_snapshot_worker/JSHeapSnapshot.js',
+            'front_end/platform/Promise.js',
+            'front_end/platform/utilities.js',
             'front_end/profiler/HeapSnapshotCommon.js',
         ],
         'devtools_layers_js_files': [
@@ -446,7 +450,8 @@
             'front_end/cm/javascript.js',
             'front_end/cm/xml.js',
             'front_end/common/WebInspector.js',
-            'front_end/common/utilities.js',
+            'front_end/platform/Promise.js',
+            'front_end/platform/utilities.js',
             'front_end/script_formatter_worker/CSSFormatter.js',
             'front_end/script_formatter_worker/JavaScriptFormatter.js',
             'front_end/script_formatter_worker/ScriptFormatterWorker.js',