Allow pressing up to enter emoji suggestion popup

Updated according to UX designer.

Bug: 1109570
Change-Id: I0a39e294dd023241680a936e2551f160307402b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2319806Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: My Nguyen <myy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791703}

chrome/browser/chromeos/input_method/emoji_suggester.cc

@@ -150,8 +150,8 @@ SuggestionStatus EmojiSuggester::HandleKeyEvent(
     return SuggestionStatus::kDismiss;
   }
   if (highlighted_index_ == kNoneHighlighted && buttons_.size() > 0) {
-    if (event.key == "Down") {
-      highlighted_index_ = 0;
+    if (event.key == "Down" || event.key == "Up") {
+      highlighted_index_ = event.key == "Down" ? 0 : buttons_.size() - 1;
       ShowSuggestionWindowWithIndices(true);
       SetButtonHighlighted(buttons_[highlighted_index_], true);
       return SuggestionStatus::kBrowsing;

chrome/browser/chromeos/input_method/emoji_suggester_unittest.cc

@@ -168,20 +168,10 @@ TEST_F(EmojiSuggesterTest, ReturnkBrowsingWhenPressingDown) {
             emoji_suggester_->HandleKeyEvent(event));
 }
 
-TEST_F(EmojiSuggesterTest, ReturnkNotHandledWhenPressingUp) {
+TEST_F(EmojiSuggesterTest, ReturnkBrowsingWhenPressingUp) {
   EXPECT_TRUE(emoji_suggester_->Suggest(base::UTF8ToUTF16("happy ")));
   InputMethodEngineBase::KeyboardEvent event;
   event.key = "Up";
-  EXPECT_EQ(SuggestionStatus::kNotHandled,
-            emoji_suggester_->HandleKeyEvent(event));
-}
-
-TEST_F(EmojiSuggesterTest, ReturnkBrowsingWhenPressingDownAndUp) {
-  EXPECT_TRUE(emoji_suggester_->Suggest(base::UTF8ToUTF16("happy ")));
-  // Go into the window.
-  Press("Down");
-  InputMethodEngineBase::KeyboardEvent event;
-  event.key = "Up";
   EXPECT_EQ(SuggestionStatus::kBrowsing,
             emoji_suggester_->HandleKeyEvent(event));
 }