Add mechanism to auto mount file systems in response to a URL request.

webkit/browser/fileapi/file_system_context.h

Index: webkit/browser/fileapi/file_system_context.h
diff --git a/webkit/browser/fileapi/file_system_context.h b/webkit/browser/fileapi/file_system_context.h
index 62841d19dc82d93e3bbc92674227fe36d82729f6..ba91af7ef97b9510c00018581b385c2a5988d990 100644
--- a/webkit/browser/fileapi/file_system_context.h
+++ b/webkit/browser/fileapi/file_system_context.h
@@ -38,6 +38,10 @@ class QuotaManagerProxy;
 class SpecialStoragePolicy;
 }
 
+namespace net {
+class URLRequest;
+}
+
 namespace webkit_blob {
 class BlobURLRequestJobTest;
 class FileStreamReader;
@@ -65,6 +69,18 @@ class SandboxFileSystemBackend;
 struct DefaultContextDeleter;
 struct FileSystemInfo;
 
+// An auto mount handler will attempt to mount the file system requested in
+// |url_request|. If the URL is for this auto mount handler, it returns true
+// and calls |callback| when the attempt is complete. If the auto mounter
+// does not recognize the URL, it returns false and does not call |callback|.
+// Called on the IO thread.
+typedef base::Callback<bool(
+    const net::URLRequest* url_request,
+    const FileSystemURL& filesystem_url,
+    const std::string& storage_domain,
+    const base::Callback<void(base::File::Error result)>& callback)>
+        URLRequestAutoMountHandler;
+
 // This class keeps and provides a file system context for FileSystem API.
 // An instance of this class is created and owned by profile.
 class WEBKIT_STORAGE_BROWSER_EXPORT FileSystemContext
@@ -95,6 +111,10 @@ class WEBKIT_STORAGE_BROWSER_EXPORT FileSystemContext
   // to serve filesystem requests for non-regular types.
   // If none is given, this context only handles HTML5 Sandbox FileSystem
   // and Drag-and-drop Isolated FileSystem requests.
+  //
+  // |auto_mount_handlers| are used to resolve calls to
+  // AttemptAutoMountForURLRequest. Only external filesystems are auto mounted
+  // when a filesystem: URL request is made.
   FileSystemContext(
       base::SingleThreadTaskRunner* io_task_runner,
       base::SequencedTaskRunner* file_task_runner,
@@ -102,6 +122,7 @@ class WEBKIT_STORAGE_BROWSER_EXPORT FileSystemContext
       quota::SpecialStoragePolicy* special_storage_policy,
       quota::QuotaManagerProxy* quota_manager_proxy,
       ScopedVector<FileSystemBackend> additional_backends,
+      const std::vector<URLRequestAutoMountHandler>& auto_mount_handlers,
       const base::FilePath& partition_path,
       const FileSystemOptions& options);
 
@@ -193,6 +214,13 @@ class WEBKIT_STORAGE_BROWSER_EXPORT FileSystemContext
       const FileSystemURL& url,
       const ResolveURLCallback& callback);
 
+  // Attempts to mount the filesystem needed to satisfy |url_request| made
+  // from |storage_domain|. If an appropriate file system is not found,
+  // callback will return an error.
+  void AttemptAutoMountForURLRequest(const net::URLRequest* url_request,
+                                     const std::string& storage_domain,
+                                     const StatusCallback& callback);
+
   // Deletes the filesystem for the given |origin_url| and |type|. This should
   // be called on the IO thread.
   void DeleteFileSystem(
@@ -343,6 +371,8 @@ class WEBKIT_STORAGE_BROWSER_EXPORT FileSystemContext
   scoped_ptr<PluginPrivateFileSystemBackend> plugin_private_backend_;
   ScopedVector<FileSystemBackend> additional_backends_;
 
+  std::vector<URLRequestAutoMountHandler> auto_mount_handlers_;
+
   // Registered file system backends.
   // The map must be constructed in the constructor since it can be accessed
   // on multiple threads.