Be explicit about target type in platform_util::OpenItem()

chrome/browser/platform_util.h

Index: chrome/browser/platform_util.h
diff --git a/chrome/browser/platform_util.h b/chrome/browser/platform_util.h
index 3e9346964fe4e399e3a47e4109521577fc41c7d5..f45e3a580fd5f92cb8df5c315bd4aad3f5f59ec4 100644
--- a/chrome/browser/platform_util.h
+++ b/chrome/browser/platform_util.h
@@ -7,6 +7,7 @@
 
 #include <string>
 
+#include "base/callback_forward.h"
 #include "base/strings/string16.h"
 #include "ui/gfx/native_widget_types.h"
 
@@ -19,15 +20,45 @@ class FilePath;
 
 namespace platform_util {
 
-// Show the given file in a file manager. If possible, select the file.
-// The |profile| is used to determine the running profile of file manager app
-// in Chrome OS only. Not used in other platforms.
-// Must be called from the UI thread.
+// Result of calling OpenFile() or OpenFolder() passed into OpenOperationResult.
+enum OpenOperationResult {
+  OPEN_SUCCEEDED,
+  OPEN_FAILED_PATH_NOT_FOUND,  // Specified path does not exist.
+  OPEN_FAILED_INVALID_TYPE,  // Type of object found at path did not match what
+                             // was expected. I.e. OpenFile was called on a
+                             // folder or OpenFolder called on a file.
+  OPEN_FAILED_NO_HANLDER_FOR_FILE_TYPE,  // There was no file handler capable of
+                                         // opening file. Only returned on
+                                         // ChromeOS.
+  OPEN_FAILED_FILE_ERROR,  // Open operation failed due to some other file
+                           // error.
+};
+
+// Callback used with OpenFile and OpenFolder.
+typedef base::Callback<void(OpenOperationResult)> OpenOperationCallback;
+
+// Opens the folder containing the item specified by |full_path| in the
+// desktop's default manner. If possible, the item will be selected. The
+// |profile| is used to determine the running profile of file manager app in
+// Chrome OS only. Not used in other platforms. Must be called on the UI
+// thread.
 void ShowItemInFolder(Profile* profile, const base::FilePath& full_path);
 
-// Open the given file in the desktop's default manner.
-// Must be called from the UI thread.
-void OpenItem(Profile* profile, const base::FilePath& full_path);
+// Opens the file specified by |full_path| in the desktop's default manner.
+// |callback| will be invoked on the UI thread with the result of the open
+// operation. |full_path| must point to a valid file. If it doesn't exist or is
+// not a file, the corresponding error will be returned to |callback|.
+void OpenFile(Profile* profile,
+              const base::FilePath& full_path,
+              const OpenOperationCallback& callback);
+
+// Opens the folder specified by |full_path| in the desktop's default manner.
+// |callback| will be invoked on the UI thread with the result of the open
+// operation. |full_path| must be an existing directory. If not, the
+// corresponding error will be returned to |callback|.
+void OpenFolder(Profile* profile,
+                const base::FilePath& full_path,
+                const OpenOperationCallback& callback);
 
 // Open the given external protocol URL in the desktop's default manner.
 // (For example, mailto: URLs in the default mail user agent.)