Fix left/right detection of inline comments in unified view

Summary:
Ref T2009. Currently, the code figures out if a comment is on the left or right by looking at the `<th />` preceeding the enclosing `<td />`.

This gets the right result in 2-up, but in 1-up rows are always `<th />`, `<th />`, `<td />`, so it always detects every inline as being in the new file.

Because "old" and "new" cells aren't inherently distingushable in the 1up view, we can't use a DOM test for this at all. Instead, just track this state explicitly.

Test Plan:
  - Made left/right comments in 1up view and 2up view.
  - Viewed them in 1up and 2up views.
  - Hovered in 1up and 2up views.
  - Diff-of-diff'd and reviewed old/new comments, then made some more.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T2009

Differential Revision: https://secure.phabricator.com/D12011

src/infrastructure/diff/PhabricatorInlineCommentController.php

@@ -201,6 +201,7 @@ abstract class PhabricatorInlineCommentController
       ->setUser($user)
       ->setSubmitURI($request->getRequestURI())
       ->setOnRight($this->getIsOnRight())
+      ->setIsNewFile($this->getIsNewFile())
       ->setNumber($this->getLineNumber())
       ->setLength($this->getLineLength())
       ->setRenderer($this->getRenderer());

src/infrastructure/diff/view/PHUIDiffInlineCommentDetailView.php

@@ -78,6 +78,7 @@ final class PHUIDiffInlineCommentDetailView
       'id' => $inline->getID(),
       'number' => $inline->getLineNumber(),
       'length' => $inline->getLineLength(),
+      'isNewFile' => (bool)$inline->getIsNewFile(),
       'on_right' => $this->onRight,
       'original' => $inline->getContent(),
     );

src/infrastructure/diff/view/PHUIDiffInlineCommentEditView.php

@@ -10,6 +10,16 @@ final class PHUIDiffInlineCommentEditView
   private $number;
   private $length;
   private $renderer;
+  private $isNewFile;
+
+  public function setIsNewFile($is_new_file) {
+    $this->isNewFile = $is_new_file;
+    return $this;
+  }
+
+  public function getIsNewFile() {
+    return $this->isNewFile;
+  }
 
   public function getIsOnRight() {
     return $this->onRight;
@@ -160,7 +170,8 @@ final class PHUIDiffInlineCommentEditView
         'class' => 'differential-inline-comment-edit',
         'sigil' => 'differential-inline-comment',
         'meta' => array(
-          'on_right' => $this->onRight,
+          'on_right' => $this->getIsOnRight(),
+          'isNewFile' => (bool)$this->getIsNewFile(),
           'number' => $this->number,
           'length' => $this->length,
         ),