Fix filesystem API file_handlers to work for drive on ChromeOS.

chrome/browser/extensions/platform_app_launcher.cc

Index: chrome/browser/extensions/platform_app_launcher.cc
diff --git a/chrome/browser/extensions/platform_app_launcher.cc b/chrome/browser/extensions/platform_app_launcher.cc
index 78548d843f1770c1da2402e30cb077b8a1116dac..fa78dbc7b833f3fbaab3321d1b560cc2243d24da 100644
--- a/chrome/browser/extensions/platform_app_launcher.cc
+++ b/chrome/browser/extensions/platform_app_launcher.cc
@@ -29,6 +29,13 @@
 #include "webkit/fileapi/file_system_types.h"
 #include "webkit/fileapi/isolated_context.h"
 
+#if defined(OS_CHROMEOS)
+#include "chrome/browser/chromeos/drive/drive_file_error.h"
+#include "chrome/browser/chromeos/drive/drive_file_system_interface.h"
+#include "chrome/browser/chromeos/drive/drive_file_system_util.h"
+#include "chrome/browser/chromeos/drive/drive_system_service.h"
+#endif
+
 using content::BrowserThread;
 using extensions::app_file_handler_util::FileHandlerForId;
 using extensions::app_file_handler_util::FileHandlerCanHandleFileWithMimeType;
@@ -92,6 +99,7 @@ class PlatformAppPathLauncher
       : profile_(profile),
         extension_(extension),
         file_path_(file_path),
+        file_system_type_(fileapi::kFileSystemTypeUnknown),
         handler_id_("") {}
 
   void Launch() {
@@ -102,6 +110,14 @@ class PlatformAppPathLauncher
     }
 
     DCHECK(file_path_.IsAbsolute());
+#if defined(OS_CHROMEOS)
+    if (drive::util::IsUnderDriveMountPoint(file_path_)) {
+      file_system_type_ = fileapi::kFileSystemTypeDrive;
+      GetMimeTypeAndLaunchForDriveFile();
+      return;
+    }
+#endif
+    file_system_type_ = fileapi::kFileSystemTypeNativeLocal;
     BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE, base::Bind(
             &PlatformAppPathLauncher::GetMimeTypeAndLaunch, this));
   }
@@ -141,6 +157,33 @@ class PlatformAppPathLauncher
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
             &PlatformAppPathLauncher::LaunchWithMimeType, this, mime_type));
   }
+#if defined(OS_CHROMEOS)
+  void GetMimeTypeAndLaunchForDriveFile() {

[benwells, 2013/03/04 01:27:39]

Can this run on any thread? It is currently on UI, if that's where it needs to
be it should have a DCHECK for that. If it can run anywhere maybe a comment
saying it is on the UI thread is warranted.

[tbarzic, 2013/03/06 01:45:10]

It _must_ run on UI thread, added DCHECK.

+    drive::DriveSystemService* service =
+        drive::DriveSystemServiceFactory::FindForProfile(profile_);
+    if (!service) {
+      LaunchWithNoLaunchData();
+      return;
+    }
+
+    service->file_system()->GetFileByPath(
+        drive::util::ExtractDrivePath(file_path_),
+        base::Bind(&PlatformAppPathLauncher::OnGotDriveFile, this));
+  }
+
+  void OnGotDriveFile(drive::DriveFileError error,

[benwells, 2013/03/04 01:27:39]

Same question here about threads. This file is pretty confusing with all the
thread bouncing, so anything to help with that is good.

[tbarzic, 2013/03/06 01:45:10]

Done.

+                      const base::FilePath& file_path,
+                      const std::string& mime_type,
+                      drive::DriveFileType file_type) {
+    if (error != drive::DRIVE_FILE_OK || mime_type.empty() ||
+        file_type != drive::REGULAR_FILE) {
+      LaunchWithNoLaunchData();
+      return;
+    }
+
+    LaunchWithMimeType(mime_type);
+  }
+#endif  // defined(OS_CHROMEOS)
 
   void LaunchWithNoLaunchData() {
     // This method is required as an entry point on the UI thread.
@@ -217,7 +260,7 @@ class PlatformAppPathLauncher
         fileapi::IsolatedContext::GetInstance();
     DCHECK(isolated_context);
     std::string filesystem_id = isolated_context->RegisterFileSystemForPath(
-        fileapi::kFileSystemTypeNativeLocal, file_path_, &registered_name);
+        file_system_type_, file_path_, &registered_name);

[benwells, 2013/03/04 01:27:39]

There will need to be a similar type of addition to the file_system_api code.

[tbarzic, 2013/03/06 01:45:10]

yes, I know.. or fileapi layer should be changed so using
kFileSystemTypeNativeLocal works for all isolated fs' registered here (and
determining the file system type on cros file system is done before/while
executing filesystem operations)

[kinaba, 2013/03/06 02:00:42]

I feel it a little strange that the client code of IsolatedContext needs to
differentiate Drive and Native paths by itself.
(Or if it needs to specify kFileSystemTypeNativeLocal for Drive paths even.)

Can't we refactor the stuffs to allow fileapi::kFileSystemTypeExternal to be
specified here?
I'm guessing we can if we employ recursive cracking of URL.

[tbarzic, 2013/03/06 02:13:00]

yeah, I agree, that's the biggest issue I have with this.. it seems recursive
cracking on URL is probably the way to go.. I'm a bit busy with some more
pressing bugs, but I think I'll be able to return to this some time next week..

and yeah using kFileSystemNativeLocal here seems a bit confusing, we should
probably use another constant to declare this type (but I don't think
kFileSystemTypeExternal is the best choice either)

     // Granting read file system permission as well to allow file-system
     // read operations.
     policy->GrantReadFileSystem(renderer_id, filesystem_id);
@@ -233,6 +276,8 @@ class PlatformAppPathLauncher
   const Extension* extension_;
   // The path to be passed through to the app.
   const base::FilePath file_path_;
+  // The file system type for the path passed through to the app.
+  fileapi::FileSystemType file_system_type_;
   // The ID of the file handler used to launch the app.
   std::string handler_id_;