[FileBrowser] Added DefaultAction dialog to choose default action.

chrome/common/extensions/api/file_browser_private.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace":"fileBrowserPrivate",
     "nodoc": "true",
     "types": [
       {
@@ skipping 370 matching lines @@
                 "name": "success",
                 "type": "boolean",
                 "optional": true,
                 "description": "True of task execution was successfully initiated."
               }
             ]
           }
         ]
       },
       {
+        "name": "setDefaultTask",
+        "description": "Sets default task.",
+        "parameters": [
+          {
+            "name": "taskId",
+            "type": "string",
+            "description": "The unique identifier of task to mark as default."
+          },
+          {
+            "name": "callback",
+            "type": "function",
+            "optional": true,
+            "parameters": [
+              {
+                "name": "success",
+                "type": "boolean",
+                "optional": true,

[asargent_no_longer_on_chrome, 2012/05/22 16:46:24]

nit: I'm not sure of your use cases, but it seems like you'd want this boolean
to be non-optional, since making the task default either succeeded or it didn't.
"Do or do not, there is no try" as Yoda says.

Also, if you wanted you could forgo having the explicit boolean for success
altogether, and instead just set chrome.extension.lastError (by returning false
instead of true from your ExtensionFunction subclass in the browser process) if
the call failed for some reason.

+                "description": "True if task successfully made default."
+              }
+            ]
+          }
+        ]        
+      },
+      {
         "name": "getFileTasks",
         "description": "Gets the list of tasks that can be performed over selected files.",
         "parameters": [
           {
             "name": "fileURLs",
             "type": "array",
             "description": "Array of selected file URLs",
             "items": { "type": "string" }
           },
           {
@@ skipping 614 matching lines @@
       },
       {
         "name": "onNetworkConnectionChanged",
         "type": "function",
         "description": "Fired when the active network connection state changes. The network connection state can be retrieved via 'getNetworkConnectionState'.",
         "parameters": []
       }
     ]
   }
 ]