Enabled pressing TAB to cycle through the Omnibox results.

chrome/browser/ui/omnibox/omnibox_view_browsertest.cc

Index: chrome/browser/ui/omnibox/omnibox_view_browsertest.cc
===================================================================
--- chrome/browser/ui/omnibox/omnibox_view_browsertest.cc	(revision 118845)
+++ chrome/browser/ui/omnibox/omnibox_view_browsertest.cc	(working copy)
@@ -747,7 +747,7 @@
     // Keyword should also be accepted by typing an ideographic space.
     omnibox_view->OnBeforePossibleChange();
     omnibox_view->SetWindowTextAndCaretPos(text + WideToUTF16(L"\x3000"),
-                                        text.length() + 1);
+                                        text.length() + 1, false, false);
     omnibox_view->OnAfterPossibleChange();
     ASSERT_FALSE(omnibox_view->model()->is_keyword_hint());
     ASSERT_EQ(text, omnibox_view->model()->keyword());
@@ -762,7 +762,7 @@
     // Keyword shouldn't be accepted by pressing space with a trailing
     // whitespace.
     omnibox_view->SetWindowTextAndCaretPos(
-        text + char16(' '), text.length() + 1);
+        text + char16(' '), text.length() + 1, false, false);
     ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_SPACE, 0));
     ASSERT_TRUE(omnibox_view->model()->is_keyword_hint());
     ASSERT_EQ(text, omnibox_view->model()->keyword());
@@ -799,7 +799,7 @@
     omnibox_view->OnBeforePossibleChange();
     omnibox_view->model()->on_paste();
     omnibox_view->SetWindowTextAndCaretPos(text + ASCIIToUTF16(" bar"),
-                                        text.length() + 4);
+                                        text.length() + 4, false, false);
     omnibox_view->OnAfterPossibleChange();
     ASSERT_FALSE(omnibox_view->model()->is_keyword_hint());
     ASSERT_TRUE(omnibox_view->model()->keyword().empty());
@@ -1013,59 +1013,94 @@
     ASSERT_TRUE(omnibox_view->IsSelectAll());
   }
 
-  void TabMoveCursorToEndTest() {
+  void TabAcceptKeyword() {
     OmniboxView* omnibox_view = NULL;
     ASSERT_NO_FATAL_FAILURE(GetOmniboxView(&omnibox_view));
 
-    omnibox_view->SetUserText(ASCIIToUTF16("Hello world"));
+    string16 text = ASCIIToUTF16(kSearchKeyword);
 
-    // Move cursor to the beginning.
-#if defined(OS_MACOSX)
-    // Home doesn't work on Mac trybot.
-    ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_A, ui::EF_CONTROL_DOWN));
-#else
-    ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_HOME, 0));
-#endif
+    // Trigger keyword hint mode.
+    ASSERT_NO_FATAL_FAILURE(SendKeySequence(kSearchKeywordKeys));
+    ASSERT_TRUE(omnibox_view->model()->is_keyword_hint());
+    ASSERT_EQ(text, omnibox_view->model()->keyword());
+    ASSERT_EQ(text, omnibox_view->GetText());
 
-    size_t start, end;
-    omnibox_view->GetSelectionBounds(&start, &end);
-    EXPECT_EQ(0U, start);
-    EXPECT_EQ(0U, end);
-
-    // Pressing tab should move cursor to the end.
+    // Trigger keyword mode by tab.
     ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_TAB, 0));
+    ASSERT_FALSE(omnibox_view->model()->is_keyword_hint());
+    ASSERT_EQ(text, omnibox_view->model()->keyword());
+    ASSERT_TRUE(omnibox_view->GetText().empty());
 
-    omnibox_view->GetSelectionBounds(&start, &end);
-    EXPECT_EQ(omnibox_view->GetText().size(), start);
-    EXPECT_EQ(omnibox_view->GetText().size(), end);
+    // Revert to keyword hint mode.
+    ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_BACK, 0));
+    ASSERT_TRUE(omnibox_view->model()->is_keyword_hint());
+    ASSERT_EQ(text, omnibox_view->model()->keyword());
+    ASSERT_EQ(text, omnibox_view->GetText());
 
     // The location bar should still have focus.
     ASSERT_TRUE(ui_test_utils::IsViewFocused(browser(),
                                              location_bar_focus_view_id_));
 
-    // Select all text.
-    omnibox_view->SelectAll(true);
-    EXPECT_TRUE(omnibox_view->IsSelectAll());
-    omnibox_view->GetSelectionBounds(&start, &end);
-    EXPECT_EQ(0U, start);
-    EXPECT_EQ(omnibox_view->GetText().size(), end);
-
-    // Pressing tab should move cursor to the end.
+    // Trigger keyword mode by tab.
     ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_TAB, 0));
+    ASSERT_FALSE(omnibox_view->model()->is_keyword_hint());
+    ASSERT_EQ(text, omnibox_view->model()->keyword());
+    ASSERT_TRUE(omnibox_view->GetText().empty());
 
-    omnibox_view->GetSelectionBounds(&start, &end);
-    EXPECT_EQ(omnibox_view->GetText().size(), start);
-    EXPECT_EQ(omnibox_view->GetText().size(), end);
+    // Revert to keyword hint mode with SHIFT+TAB.
+#if defined(OS_MACOSX)
+    ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_BACKTAB, 0));
+#else
+    ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_TAB, ui::EF_SHIFT_DOWN));
+#endif
+    ASSERT_TRUE(omnibox_view->model()->is_keyword_hint());
+    ASSERT_EQ(text, omnibox_view->model()->keyword());
+    ASSERT_EQ(text, omnibox_view->GetText());
 
-    // The location bar should still have focus.
     ASSERT_TRUE(ui_test_utils::IsViewFocused(browser(),
                                              location_bar_focus_view_id_));
+  }
 
-    // Pressing tab when cursor is at the end should change focus.
+  void TabTraverseResultsTest() {
+    OmniboxView* omnibox_view = NULL;
+    ASSERT_NO_FATAL_FAILURE(GetOmniboxView(&omnibox_view));
+    AutocompletePopupModel* popup_model = omnibox_view->model()->popup_model();
+    ASSERT_TRUE(popup_model);
+
+    // Input something to trigger results.
+    ASSERT_NO_FATAL_FAILURE(SendKeySequence(kDesiredTLDKeys));
+    ASSERT_NO_FATAL_FAILURE(WaitForAutocompleteControllerDone());
+    ASSERT_TRUE(popup_model->IsOpen());
+
+    size_t old_selected_line = popup_model->selected_line();
+    EXPECT_EQ(0U, old_selected_line);
+
+    // Move down the results.
+    size_t size = popup_model->result().size();

[Peter Kasting, 2012/01/25 05:53:05]

Nit: Optional form:

    for (size_t size = popup_model->result().size();
         popup_model->selected_line() < (size - 1);
         old_selected_line = popup_model->selected_line()) {
      ...

I personally like this because it scopes |size| to the loop.  Up to you. 
(Variants usable below as well)

+    while (popup_model->selected_line() < size - 1) {
+      ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_TAB, 0));
+      ASSERT_LT(old_selected_line, popup_model->selected_line());
+      old_selected_line = popup_model->selected_line();
+    }
+
+    // Don't move past the end.
     ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_TAB, 0));
+    ASSERT_EQ(old_selected_line, popup_model->selected_line());
+    ASSERT_TRUE(ui_test_utils::IsViewFocused(browser(),
+                                             location_bar_focus_view_id_));
 
-    ASSERT_FALSE(ui_test_utils::IsViewFocused(browser(),
-                                              location_bar_focus_view_id_));
+    // Move back up the results.
+    while (popup_model->selected_line() > 0U) {
+      ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_TAB, ui::EF_SHIFT_DOWN));
+      ASSERT_GT(old_selected_line, popup_model->selected_line());
+      old_selected_line = popup_model->selected_line();
+    }
+
+    // Don't move past the beginning.
+    ASSERT_NO_FATAL_FAILURE(SendKey(ui::VKEY_TAB, ui::EF_SHIFT_DOWN));
+    ASSERT_EQ(0U, popup_model->selected_line());
+    ASSERT_TRUE(ui_test_utils::IsViewFocused(browser(),
+                                             location_bar_focus_view_id_));
   }
 
   void PersistKeywordModeOnTabSwitch() {
@@ -1191,10 +1226,17 @@
   DeleteItemTest();
 }
 
-IN_PROC_BROWSER_TEST_F(OmniboxViewTest, TabMoveCursorToEnd) {
-  TabMoveCursorToEndTest();
+IN_PROC_BROWSER_TEST_F(OmniboxViewTest, TabAcceptKeyword) {
+  TabAcceptKeyword();
 }
 
+#if !defined(OS_MACOSX)
+// Mac intentionally does not support this behavior.
+IN_PROC_BROWSER_TEST_F(OmniboxViewTest, TabTraverseResultsTest) {
+  TabTraverseResultsTest();
+}
+#endif
+
 IN_PROC_BROWSER_TEST_F(OmniboxViewTest,
                        PersistKeywordModeOnTabSwitch) {
   PersistKeywordModeOnTabSwitch();