Mount MTP devices in Chrome OS Files.app.

chrome/browser/chromeos/fileapi/file_system_backend.cc

Index: chrome/browser/chromeos/fileapi/file_system_backend.cc
diff --git a/chrome/browser/chromeos/fileapi/file_system_backend.cc b/chrome/browser/chromeos/fileapi/file_system_backend.cc
index 62ced143f511537ce8ae8cd9e6951db6e0e62c78..256130a4212941807f1414b4b3ec72886b1f166a 100644
--- a/chrome/browser/chromeos/fileapi/file_system_backend.cc
+++ b/chrome/browser/chromeos/fileapi/file_system_backend.cc
@@ -9,6 +9,7 @@
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/chromeos/fileapi/file_access_permissions.h"
 #include "chrome/browser/chromeos/fileapi/file_system_backend_delegate.h"
+#include "chrome/browser/media_galleries/fileapi/media_file_system_backend.h"
 #include "chromeos/dbus/cros_disks_client.h"
 #include "webkit/browser/blob/file_stream_reader.h"
 #include "webkit/browser/fileapi/async_file_util.h"
@@ -28,10 +29,12 @@ bool FileSystemBackend::CanHandleURL(const fileapi::FileSystemURL& url) {
   return url.type() == fileapi::kFileSystemTypeNativeLocal ||
          url.type() == fileapi::kFileSystemTypeRestrictedNativeLocal ||
          url.type() == fileapi::kFileSystemTypeDrive ||
-         url.type() == fileapi::kFileSystemTypeProvided;
+         url.type() == fileapi::kFileSystemTypeProvided ||
+         url.type() == fileapi::kFileSystemTypeDeviceMediaAsFileStorage;
 }
 
 FileSystemBackend::FileSystemBackend(
+    const base::FilePath& profile_path,
     FileSystemBackendDelegate* drive_delegate,
     FileSystemBackendDelegate* file_system_provider_delegate,
     scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy,
@@ -40,6 +43,8 @@ FileSystemBackend::FileSystemBackend(
     : special_storage_policy_(special_storage_policy),
       file_access_permissions_(new FileAccessPermissions()),
       local_file_util_(fileapi::AsyncFileUtil::CreateForLocalFileSystem()),
+      device_media_async_file_util_(
+          DeviceMediaAsyncFileUtil::Create(profile_path)),
       drive_delegate_(drive_delegate),
       file_system_provider_delegate_(file_system_provider_delegate),
       mount_points_(mount_points),
@@ -76,6 +81,7 @@ bool FileSystemBackend::CanHandleType(fileapi::FileSystemType type) const {
     case fileapi::kFileSystemTypeRestrictedNativeLocal:
     case fileapi::kFileSystemTypeNativeLocal:
     case fileapi::kFileSystemTypeNativeForPlatformApp:
+    case fileapi::kFileSystemTypeDeviceMediaAsFileStorage:
       return true;
     default:
       return false;
@@ -225,6 +231,8 @@ fileapi::AsyncFileUtil* FileSystemBackend::GetAsyncFileUtil(
     case fileapi::kFileSystemTypeNativeLocal:
     case fileapi::kFileSystemTypeRestrictedNativeLocal:
       return local_file_util_.get();
+    case fileapi::kFileSystemTypeDeviceMediaAsFileStorage:
+        return device_media_async_file_util_.get();
     default:
       NOTREACHED();
   }
@@ -252,10 +260,12 @@ fileapi::FileSystemOperation* FileSystemBackend::CreateFileSystemOperation(
 
   DCHECK(url.type() == fileapi::kFileSystemTypeNativeLocal ||
          url.type() == fileapi::kFileSystemTypeRestrictedNativeLocal ||
-         url.type() == fileapi::kFileSystemTypeDrive);
+         url.type() == fileapi::kFileSystemTypeDrive ||
+         url.type() == fileapi::kFileSystemTypeDeviceMediaAsFileStorage);
   return fileapi::FileSystemOperation::Create(
       url, context,
-      make_scoped_ptr(new fileapi::FileSystemOperationContext(context)));
+      make_scoped_ptr(new fileapi::FileSystemOperationContext(
+          context, MediaFileSystemBackend::MediaTaskRunner())));

[vandebo (ex-Chrome), 2014/04/23 16:24:44]

Passing in the media task runner here will do the file operations for all fs
types on that thread.  I'm not sure, but there are thread ordering restrictions
on the MTP code, so I'd feel safer if the MTP operations where on the media task
runner, but I don't think you want to do everything on that task runner.

[kinaba, 2014/04/24 01:33:30]

Right. I can't remember why I wrote it like the first patchset...

 }
 
 bool FileSystemBackend::SupportsStreaming(
@@ -286,6 +296,12 @@ FileSystemBackend::CreateFileStreamReader(
       return scoped_ptr<webkit_blob::FileStreamReader>(
           webkit_blob::FileStreamReader::CreateForFileSystemFile(
               context, url, offset, expected_modification_time));
+    case fileapi::kFileSystemTypeDeviceMediaAsFileStorage:
+      // TODO(kinaba): the stream reader from device media async util limits

[vandebo (ex-Chrome), 2014/04/23 16:24:44]

I'm not sure what you mean here?

[kinaba, 2014/04/24 01:33:30]

Revised the comment. Does it make sense?

+      // itself only for reading arbitrary file types. Handle non-media files
+      // here as well.
+      return device_media_async_file_util_->GetFileStreamReader(
+          url, offset, expected_modification_time, context);
     default:
       NOTREACHED();
   }
@@ -316,6 +332,9 @@ FileSystemBackend::CreateFileStreamWriter(
     case fileapi::kFileSystemTypeRestrictedNativeLocal:
       // Restricted native local file system is read only.
       return scoped_ptr<fileapi::FileStreamWriter>();
+    case fileapi::kFileSystemTypeDeviceMediaAsFileStorage:
+      // TODO(kinaba): support writing.
+      return scoped_ptr<fileapi::FileStreamWriter>();
     default:
       NOTREACHED();
   }