Cleanup of screenshot_taker and drive_file_system_util.

According to achuith's comment on https://chromiumcodereview.appspot.com/10958025/,
I fixed the code slightly:
- gdata::util::EnsureDirectoryExists accepts FileOperationCallback rather than base::Closure
- move the callback to screenshot_taker
- cleanup code a little -- not callback.is_null() check but adding it as DCHECK()
- added a little more comments

BUG=None
TEST=compilation succeeds


Review URL: https://chromiumcodereview.appspot.com/10979039

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@159070 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 11 insertions, 19 deletions

diff --git a/chrome/browser/chromeos/gdata/drive_file_system_util.cc b/chrome/browser/chromeos/gdata/drive_file_system_util.cc
index fa8185f..7c88c26 100644
--- a/chrome/browser/chromeos/gdata/drive_file_system_util.cc
+++ b/chrome/browser/chromeos/gdata/drive_file_system_util.cc
@@ -15,6 +15,7 @@
 #include "base/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/logging.h"
+#include "base/message_loop_proxy.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
@@ -176,19 +177,6 @@ void OnGetEntryInfoForInsertDriveCachePathsPermissions(
   callback.Run();
 }
 
-void EnsureDirectoryExistsCallback(const base::Closure& callback,
-                                   DriveFileError error) {
-  if (error != gdata::DRIVE_FILE_OK &&
-      error != gdata::DRIVE_FILE_ERROR_EXISTS) {
-    LOG(ERROR) << "Failed to ensure the existence of the specified directory "
-               << "in Google Drive: " << error;
-    return;
-  }
-
-  if (!callback.is_null())
-    callback.Run();
-}
-
 }  // namespace
 
 const FilePath& GetDriveMountPointPath() {
@@ -411,9 +399,10 @@ void PrepareWritableFileAndRun(Profile* profile,
 
 void EnsureDirectoryExists(Profile* profile,
                            const FilePath& directory,
-                           const base::Closure& callback) {
+                           const FileOperationCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
          BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(!callback.is_null());
   if (IsUnderDriveMountPoint(directory)) {
     DriveFileSystemInterface* file_system = GetDriveFileSystem(profile);
     DCHECK(file_system);
@@ -421,10 +410,10 @@ void EnsureDirectoryExists(Profile* profile,
         ExtractDrivePath(directory),
         true /* is_exclusive */,
         true /* is_recursive */,
-        base::Bind(&EnsureDirectoryExistsCallback, callback));
+        callback);
   } else {
-    if (!callback.is_null())
-      callback.Run();
+    base::MessageLoopProxy::current()->PostTask(
+        FROM_HERE, base::Bind(callback, DRIVE_FILE_OK));
   }
 }
 
diff --git a/chrome/browser/chromeos/gdata/drive_file_system_util.h b/chrome/browser/chromeos/gdata/drive_file_system_util.h
index 358e2e8..eff80bf 100644
--- a/chrome/browser/chromeos/gdata/drive_file_system_util.h
+++ b/chrome/browser/chromeos/gdata/drive_file_system_util.h
@@ -11,6 +11,7 @@
 
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
+#include "chrome/browser/chromeos/gdata/drive_resource_metadata.h"
 #include "chrome/browser/google_apis/gdata_errorcode.h"
 #include "googleurl/src/gurl.h"
 
@@ -117,7 +118,9 @@ void PrepareWritableFileAndRun(Profile* profile,
 
 // Ensures the existence of |directory| of '/special/drive/foo'.  This will
 // create |directory| and its ancestors if they don't exist.  |callback| is
-// invoked after making sure that |directory| exists.
+// invoked after making sure that |directory| exists.  |callback| should
+// interpret error codes of either DRIVE_FILE_OK or DRIVE_FILE_ERROR_EXISTS as
+// indicating that |directory| now exists.
 //
 // If |directory| is not a Drive path, it won't check the existence and just
 // runs |callback|.
@@ -125,7 +128,7 @@ void PrepareWritableFileAndRun(Profile* profile,
 // Must be called from UI/IO thread.
 void EnsureDirectoryExists(Profile* profile,
                            const FilePath& directory,
-                           const base::Closure& callback);
+                           const FileOperationCallback& callback);
 
 // Converts GData error code into file platform error code.
 DriveFileError GDataToDriveFileError(GDataErrorCode status);