[dragdrop] Clean file_transfer_controller.js whitespace

Remove a stray extra line. Add some in canPasteOrDrop_ to end the code
squishing competition and instead promote code readability.

No change in behavior, no new tests.

Tbr: (mr-no-nbn) adanilo
Bug: 1002394
Change-Id: I038646234385c7b0dd73b72752f8c5a160e70877
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2275161
Commit-Queue: Alex Danilo <adanilo@chromium.org>
Reviewed-by: Alex Danilo <adanilo@chromium.org>
Auto-Submit: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#784315}

ui/file_manager/file_manager/foreground/js/file_transfer_controller.js

@@ -1279,18 +1279,22 @@ class FileTransferController {
     if (!clipboardData) {
       return false;
     }
+
     if (!destinationEntry) {
       return false;
     }
+
     const destinationLocationInfo =
         this.volumeManager_.getLocationInfo(destinationEntry);
     if (!destinationLocationInfo || destinationLocationInfo.isReadOnly) {
       return false;
     }
+
     if (destinationLocationInfo.volumeInfo &&
         destinationLocationInfo.volumeInfo.error) {
       return false;
     }
+
     if (!clipboardData.types || clipboardData.types.indexOf('fs/tag') === -1) {
       return false;  // Unsupported type of content.
     }
@@ -1712,7 +1716,6 @@ FileTransferController.PastePlan = class {
   }
 };
 
-
 /**
  * Converts list of urls to list of Entries with granting R/W permissions to
  * them, which is essential when pasting files from a different profile.