Use scoped_ptr to document ownership in InstantUnloadHandler.

chrome/browser/instant/instant_commit_type.h

Index: chrome/browser/instant/instant_commit_type.h
diff --git a/chrome/browser/instant/instant_commit_type.h b/chrome/browser/instant/instant_commit_type.h
index 2019da40fdacffa3806ebd75a58b3183156bfe2d..c7c7da68dbea5b7d30ed608209ca4f6e0b46a7b0 100644
--- a/chrome/browser/instant/instant_commit_type.h
+++ b/chrome/browser/instant/instant_commit_type.h
@@ -5,20 +5,20 @@
 #ifndef CHROME_BROWSER_INSTANT_INSTANT_COMMIT_TYPE_H_
 #define CHROME_BROWSER_INSTANT_INSTANT_COMMIT_TYPE_H_
 
-// Reason why the Instant preview is committed (merged into a tab).
+// Reason why the Instant overlay is committed (merged into a tab).
 enum InstantCommitType {
   // The commit is due to the user pressing Enter from the omnibox.
   INSTANT_COMMIT_PRESSED_ENTER,
 
   // The commit is due to the user pressing Alt-Enter from the omnibox (which
-  // causes the preview to be committed on to a new tab).
+  // causes the overlay to be committed onto a new tab).
   INSTANT_COMMIT_PRESSED_ALT_ENTER,
 
   // The commit is due to the omnibox losing focus, usually due to the user
-  // clicking on the preview.
+  // clicking on the overlay.
   INSTANT_COMMIT_FOCUS_LOST,
 
-  // The commit is due to the instant page navigating.
+  // The commit is due to the Instant overlay navigating to a non-Instant URL.
   INSTANT_COMMIT_NAVIGATED,
 
   // The commit is due to the user clicking on a query suggestion.