Add isWritableFileEntry to the fileSystem API

chrome/browser/extensions/api/file_system/file_system_api.h

Index: chrome/browser/extensions/api/file_system/file_system_api.h
diff --git a/chrome/browser/extensions/api/file_system/file_system_api.h b/chrome/browser/extensions/api/file_system/file_system_api.h
index ec3293d4022061cda0b067e6024ba367d944de09..4b171eee6d9ea504982f7dfc9b345828c2ce740e 100644
--- a/chrome/browser/extensions/api/file_system/file_system_api.h
+++ b/chrome/browser/extensions/api/file_system/file_system_api.h
@@ -29,8 +29,6 @@ class FileSystemEntryFunction : public AsyncExtensionFunction {
 
   virtual ~FileSystemEntryFunction() {}
 
-  bool HasFileSystemWritePermission();
-
   // Called on the FILE thread. This is called when a writable file entry is
   // being returned. The function will ensure the file exists, creating it if
   // necessary, and also check that the file is not a link.
@@ -55,6 +53,15 @@ class FileSystemGetWritableFileEntryFunction : public FileSystemEntryFunction {
   virtual bool RunImpl() OVERRIDE;
 };
 
+class FileSystemIsWritableFileEntryFunction : public SyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("fileSystem.isWritableFileEntry");
+
+ protected:
+  virtual ~FileSystemIsWritableFileEntryFunction() {}
+  virtual bool RunImpl() OVERRIDE;
+};
+
 class FileSystemChooseFileFunction : public FileSystemEntryFunction {
  public:
   // Allow picker UI to be skipped in testing.