Log unique search queries entered by user.

Track number of unique search queries issued. Will be used to calculate overall Search CTR.
A unique search query is defined as whenever the search box goes from empty to non-empty.

TBR=holte@chromium.org

Bug: 1035529
Change-Id: Iaeadb897c5ad86ba6a65c9b49edb4ff8fb427d4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1977187
Commit-Queue: Jenny Zhang <jennyz@chromium.org>
Reviewed-by: Andrew Xu <andrewxu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#729549}

ash/app_list/views/search_box_view.cc

@@ -80,6 +80,12 @@ float GetAssistantButtonOpacityForState(AppListState state) {
   return 1.f;
 }
 
+bool IsTrimmedQueryEmpty(const base::string16& query) {
+  base::string16 trimmed_query;
+  base::TrimWhitespace(query, base::TrimPositions::TRIM_ALL, &trimmed_query);
+  return trimmed_query.empty();
+}
+
 }  // namespace
 
 SearchBoxView::SearchBoxView(search_box::SearchBoxViewDelegate* delegate,
@@ -100,6 +106,7 @@ void SearchBoxView::Init(bool is_tablet_mode) {
   if (app_list_features::IsZeroStateSuggestionsEnabled())
     set_show_close_button_when_active(true);
   SearchBoxViewBase::Init();
+  current_query_ = search_box()->GetText();
 }
 
 void SearchBoxView::ResetForShow() {
@@ -115,6 +122,7 @@ void SearchBoxView::ResetForShow() {
 
 void SearchBoxView::ClearSearch() {
   search_box::SearchBoxViewBase::ClearSearch();
+  current_query_.clear();
   app_list_view_->SetStateFromSearchBoxView(
       true, false /*triggered_by_contents_change*/);
 }
@@ -494,6 +502,12 @@ void SearchBoxView::ClearAutocompleteText() {
 
 void SearchBoxView::ContentsChanged(views::Textfield* sender,
                                     const base::string16& new_contents) {
+  if (IsTrimmedQueryEmpty(current_query_) && !IsSearchBoxTrimmedQueryEmpty()) {
+    // User enters a new search query. Record the action.
+    base::RecordAction(base::UserMetricsAction("AppList_SearchQueryStarted"));
+  }
+  current_query_ = new_contents;
+
   // Update autocomplete text highlight range to track user typed text.
   if (ShouldProcessAutocomplete())
     ResetHighlightRange();

ash/app_list/views/search_box_view.h

@@ -162,6 +162,8 @@ class APP_LIST_EXPORT SearchBoxView : public search_box::SearchBoxViewBase,
   bool HandleKeyEventForDisabledSearchBoxSelection(
       const ui::KeyEvent& key_event);
 
+  base::string16 current_query_;
+
   // The range of highlighted text for autocomplete.
   gfx::Range highlight_range_;
 

ash/app_list/views/search_box_view_unittest.cc

@@ -20,6 +20,7 @@
 #include "ash/public/cpp/app_list/vector_icons/vector_icons.h"
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/metrics/user_action_tester.h"
 #include "base/test/scoped_feature_list.h"
 #include "ui/base/ime/composition_text.h"
 #include "ui/chromeos/search_box/search_box_constants.h"
@@ -417,6 +418,23 @@ TEST_F(SearchBoxViewTest, ChangeSelectionWhileResultsAreBeingRemoved) {
       result_page_view->result_selection_controller()->selected_result());
 }
 
+TEST_F(SearchBoxViewTest, NewSearchQueryActionRecordedWhenUserType) {
+  base::UserActionTester user_action_tester;
+  // User starts to type a character in search box.
+  KeyPress(ui::VKEY_A);
+  EXPECT_EQ(1, user_action_tester.GetActionCount("AppList_SearchQueryStarted"));
+
+  // User continues to type another character.
+  KeyPress(ui::VKEY_B);
+  EXPECT_EQ(1, user_action_tester.GetActionCount("AppList_SearchQueryStarted"));
+
+  // User erases the query in the search box and types a new one.
+  KeyPress(ui::VKEY_BACK);
+  KeyPress(ui::VKEY_BACK);
+  KeyPress(ui::VKEY_C);
+  EXPECT_EQ(2, user_action_tester.GetActionCount("AppList_SearchQueryStarted"));
+}
+
 class SearchBoxViewAssistantButtonTest : public SearchBoxViewTest {
  public:
   SearchBoxViewAssistantButtonTest() = default;

tools/metrics/actions/actions.xml

@@ -2485,6 +2485,13 @@ should be able to be added at any place in this file.
   <description>Please enter the description of this user action.</description>
 </action>
 
+<action name="AppList_SearchQueryStarted">
+  <owner>jennyz@chromium.org</owner>
+  <description>
+    User starts a new search query in launcher search box.
+  </description>
+</action>
+
 <action name="AppList_ShowPlayStoreQueryResults">
   <owner>jennyz@chromium.org</owner>
   <owner>newcomer@chromium.org</owner>