Significantly cleans up the ImageWriter Operation class and subclasses.

chrome/browser/extensions/api/image_writer_private/write_from_file_operation.cc

Index: chrome/browser/extensions/api/image_writer_private/write_from_file_operation.cc
diff --git a/chrome/browser/extensions/api/image_writer_private/write_from_file_operation.cc b/chrome/browser/extensions/api/image_writer_private/write_from_file_operation.cc
index 65d845759a00190181f185827594be3f7b10aba4..09c56fd33ef414df472980bb180941fb1d4cbe27 100644
--- a/chrome/browser/extensions/api/image_writer_private/write_from_file_operation.cc
+++ b/chrome/browser/extensions/api/image_writer_private/write_from_file_operation.cc
@@ -15,25 +15,27 @@ using content::BrowserThread;
 WriteFromFileOperation::WriteFromFileOperation(
     base::WeakPtr<OperationManager> manager,
     const ExtensionId& extension_id,
-    const base::FilePath& path,
-    const std::string& storage_unit_id)
-  : Operation(manager, extension_id, storage_unit_id) {
-    image_path_ = path;
+    const base::FilePath& user_file_path,
+    const std::string& device_path)
+    : Operation(manager, extension_id, device_path) {
+  image_path_ = user_file_path;
 }
 
-WriteFromFileOperation::~WriteFromFileOperation() {
-}
-
-void WriteFromFileOperation::Start() {
-  DVLOG(1) << "Starting file-to-usb write of " << image_path_.value()
-           << " to " << storage_unit_id_;
+WriteFromFileOperation::~WriteFromFileOperation() {}
 
+void WriteFromFileOperation::StartImpl() {
   if (!base::PathExists(image_path_) || base::DirectoryExists(image_path_)) {
+    DLOG(ERROR) << "Source must exist and not be a directory.";
     Error(error::kImageInvalid);
     return;
   }
 
-  WriteStart();
+  Unzip(base::Bind(
+      &WriteFromFileOperation::Write,
+      this,
+      base::Bind(&WriteFromFileOperation::VerifyWrite,
+                 this,
+                 base::Bind(&WriteFromFileOperation::Finish, this))));
 }
 
 }  // namespace image_writer