Add the boilerplate for actions to File System Provider API.

chrome/common/extensions/api/file_system_provider.idl

Index: chrome/common/extensions/api/file_system_provider.idl
diff --git a/chrome/common/extensions/api/file_system_provider.idl b/chrome/common/extensions/api/file_system_provider.idl
index cd4cd613e584ada5180751cde88faf6569e1dc72..7ec37c2af603d4938398101734a16c3c50181d10 100644
--- a/chrome/common/extensions/api/file_system_provider.idl
+++ b/chrome/common/extensions/api/file_system_provider.idl
@@ -8,7 +8,7 @@
 namespace fileSystemProvider {
   // Error codes used by providing extensions in response to requests as well
   // as in case of errors when calling methods of the API. For success,
-  // <code>OK</code> must be used.
+  // <code>"OK"</code> must be used.
   enum ProviderError {
     OK,
     FAILED,
@@ -41,6 +41,16 @@ namespace fileSystemProvider {
     DELETED
   };
 
+  // Type of an action. <code>"SHARE"</code> is for sharing files with others,
+  // <code>"PIN_TOGGLE"</code> for pinning (saving for offline access) and

[not at google - send to devlin, 2015/05/27 23:37:58]

could you call it like SAVE_OFFLINE then? "pin" seems UI dependent.

[benwells, 2015/05/28 00:17:36]

Yep it also feels like it should be two actions as well instead of a toggle
action.

[mtomasz, 2015/05/28 04:12:15]

Good idea. How to name opposite? UNSAVE_OFFLINE? How about:
MARK_FOR_OFFLINE + UNMARK_FOR_OFFLINE?

[mtomasz, 2015/06/23 02:05:36]

Done.

+  // unpinning. <code>"CUSTOM"</code> is used for any other custom action.
+  // Used by $(ref:onGetActionsRequested) and $(ref:onExecuteActionRequested).
+  enum ActionType {
+    SHARE,
+    PIN_TOGGLE,
+    CUSTOM
+  };
+
   // Represents metadata of a file or a directory.
   dictionary EntryMetadata {
     // True if it is a directory.
@@ -169,6 +179,18 @@ namespace fileSystemProvider {
     boolean thumbnail;
   };
 
+  // Options for the $(ref:onGetActionsRequested) event.
+  dictionary GetActionsRequestedOptions {
+    // The identifier of the file system related to this operation.
+    DOMString fileSystemId;
+
+    // The unique identifier of this request.
+    long requestId;
+
+    // The path of the entry to return the list of actions for.
+    DOMString entryPath;
+  };
+
   // Options for the $(ref:onReadDirectoryRequested) event.
   dictionary ReadDirectoryRequestedOptions {
     // The identifier of the file system related to this operation.
@@ -375,6 +397,38 @@ namespace fileSystemProvider {
     boolean recursive;
   };
 
+  // Information about an action for an entry.
+  dictionary Action {
+    // The identifier of the action.
+    DOMString id;
+
+    // The type of the action. Files app uses the <code>type</code> to render
+    // the action accordingly. For <code>"CUSTOM"</code> action type, the
+    // actions are rendered in the context menu. For other types, they may be
+    // rendered in a way consistent with other file types, eg. as a button in
+    // the Files app's header.
+    ActionType type;

[benwells, 2015/05/28 00:17:36]

Why have a type and an ID? Can we just have an ID with some known IDs?

[mtomasz, 2015/05/28 04:12:15]

I'm fine to combine. How about:

enum CommonActionId { SHARE, TOGGLE_PINNED };

Do we support IDL unions? If so, then we could use:

dictionary Action {
  (DOMString or CommonActionId) id;
}

[not at google - send to devlin, 2015/05/28 16:02:39]

That's precisely what we support, and it was even Ben that added it.

[mtomasz, 2015/06/23 02:05:36]

Sadly unions do not work when both strings and enums are used (as both are
implemented as strings). Let me use DOMString only here. Reworking the IDL code
generator would take significant time, which I believe shouldn't block this CL.

+
+    // The title of the action. Used only for the <code>"CUSTOM"</code> action
+    // type. For other types, the title is ignored.
+    DOMString? title;
+  };
+
+  // Options for the $(ref:onExecuteActionRequested) event.
+  dictionary ExecuteActionRequestedOptions {
+    // The identifier of the file system related to this operation.
+    DOMString fileSystemId;
+
+    // The unique identifier of this request.
+    long requestId;
+
+    // The path of the entry to be used for the action.
+    DOMString entryPath;
+
+    // The identifier of the action to be executed.
+    DOMString actionId;
+  };
+
   // Information about a change happened to an entry within the observed
   // directory (including the entry itself).
   dictionary Change {
@@ -434,8 +488,10 @@ namespace fileSystemProvider {
   [nocompile] callback ProviderErrorCallback = void(ProviderError error);
 
   // Success callback for the $(ref:onGetMetadataRequested) event.
-  [nocompile] callback MetadataCallback = void(
-      EntryMetadata metadata);
+  [nocompile] callback MetadataCallback = void(EntryMetadata metadata);
+
+  // Success callback for the $(ref:onGetActionsRequested) event.
+  [nocompile, nodoc] callback ActionsCallback = void(Action[] actions);
 
   // Success callback for the $(ref:onReadDirectoryRequested) event. If more
   // entries will be returned, then <code>hasMore</code> must be true, and it
@@ -538,6 +594,15 @@ namespace fileSystemProvider {
         MetadataCallback successCallback,
         ProviderErrorCallback errorCallback);
 
+    // Raised when list of actions for of a file or a directory at
+    // <code>entryPath</code>s requested. The actions must be returned with the
+    // <code>successCallback</code> call. In case of an error,
+    // <code>errorCallback</code> must be called.
+    [maxListeners=1, nodoc] static void onGetActionsRequested(
+        GetActionsRequestedOptions options,
+        ActionsCallback successCallback,
+        ProviderErrorCallback errorCallback);
+
     // Raised when contents of a directory at <code>directoryPath</code> are
     // requested. The results must be returned in chunks by calling the
     // <code>successCallback</code> several times. In case of an error,
@@ -668,6 +733,14 @@ namespace fileSystemProvider {
       RemoveWatcherRequestedOptions options,
       ProviderSuccessCallback successCallback,
       ProviderErrorCallback errorCallback);
+
+    // Raised when executing an action for a file or a directory is requested.
+    // After the action is completed, <code>successCallback</code> must be
+    // called. On error, <code>errorCallback</code> must be called.
+    [maxListeners=1, nodoc] static void onExecuteActionRequested(
+      ExecuteActionRequestedOptions options,
+      ProviderSuccessCallback successCallback,
+      ProviderErrorCallback errorCallback);
   };
 };