[omnibox] Break out SetCaretPos() method and enhance browser test

components/omnibox/browser/omnibox_edit_model.cc

Index: components/omnibox/browser/omnibox_edit_model.cc
diff --git a/components/omnibox/browser/omnibox_edit_model.cc b/components/omnibox/browser/omnibox_edit_model.cc
index e9fd507c1c66e3999e1de6bffcfd1fd5b7fe8ed6..4868f41073bc83a27576bb819519e1121b751e65 100644
--- a/components/omnibox/browser/omnibox_edit_model.cc
+++ b/components/omnibox/browser/omnibox_edit_model.cc
@@ -372,9 +372,11 @@ void OmniboxEditModel::Revert() {
   has_temporary_text_ = false;
   size_t start, end;
   view_->GetSelectionBounds(&start, &end);
-  view_->SetWindowTextAndCaretPos(permanent_text_, 0, false, false);
-  view_->SetWindowTextAndCaretPos(
-      permanent_text_, std::min(permanent_text_.length(), start), false, true);
+  // First home the cursor, so view of text is scrolled to left, then correct
+  // it. |SetCaretPos()| doesn't scroll the text, so doing that first wouldn't
+  // accomplish anything.
+  view_->SetWindowTextAndCaretPos(permanent_text_, 0, false, true);
+  view_->SetCaretPos(std::min(permanent_text_.length(), start));
   client_->OnRevert();
 }