Add reopen closed tab IPH feature and event definitions

This adds the feature and event definitions to the IPH backend for our
desktop IPH pilot feature: recommending users reopen accidentally
closed tabs. See associated issue for design doc, PRD, and mocks.

Bug: 887991
Change-Id: I939b0b8de95d7340d902ad2273c8bae0a751f12e
Reviewed-on: https://chromium-review.googlesource.com/c/1259476Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Collin Baker <collinbaker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596366}

components/feature_engagement/public/event_constants.cc

@@ -22,6 +22,7 @@ const char kIncognitoWindowOpened[] = "incognito_window_opened";
 const char kIncognitoWindowSessionTimeMet[] =
     "incognito_window_session_time_met";
 
+const char kReopenTabConditionsMet[] = "reopen_tab_conditions_met";
 #endif  // BUILDFLAG(ENABLE_DESKTOP_IN_PRODUCT_HELP)
 
 #if defined(OS_WIN) || defined(OS_LINUX) || defined(OS_IOS)

components/feature_engagement/public/event_constants.h

@@ -40,6 +40,11 @@ extern const char kIncognitoWindowOpened[];
 // IncognitoWindowPromo by accumulating 2 hours of active session time (one-off
 // event).
 extern const char kIncognitoWindowSessionTimeMet[];
+
+// All conditions for reopen closed tab IPH were met. Since this IPH needs to
+// track user events (opening/closing tabs, focusing the omnibox, etc) on the
+// second level, it must be done manually.
+extern const char kReopenTabConditionsMet[];
 #endif  // BUILDFLAG(ENABLE_DESKTOP_IN_PRODUCT_HELP)
 
 #if defined(OS_WIN) || defined(OS_LINUX) || defined(OS_IOS)

components/feature_engagement/public/feature_constants.cc

@@ -66,6 +66,8 @@ const base::Feature kIPHIncognitoWindowFeature{
     "IPH_IncognitoWindow", base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kIPHNewTabFeature{"IPH_NewTab",
                                       base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kIPHReopenTabFeature{"IPH_ReopenTab",
+                                         base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // BUILDFLAG(ENABLE_DESKTOP_IPH)
 
 #if defined(OS_IOS)

components/feature_engagement/public/feature_constants.h

@@ -48,6 +48,7 @@ extern const base::Feature kIPHPreviewsOmniboxUIFeature;
 extern const base::Feature kIPHBookmarkFeature;
 extern const base::Feature kIPHIncognitoWindowFeature;
 extern const base::Feature kIPHNewTabFeature;
+extern const base::Feature kIPHReopenTabFeature;
 #endif  // BUILDFLAG(ENABLE_DESKTOP_IPH)
 
 #if defined(OS_IOS)

components/feature_engagement/public/feature_list.cc

@@ -42,6 +42,7 @@ const base::Feature* const kAllFeatures[] = {
     &kIPHBookmarkFeature,
     &kIPHIncognitoWindowFeature,
     &kIPHNewTabFeature,
+    &kIPHReopenTabFeature,
 #endif  // BUILDFLAG(ENABLE_DESKTOP_IN_PRODUCT_HELP)
 #if defined(OS_IOS)
     &kIPHBottomToolbarTipFeature,

components/feature_engagement/public/feature_list.h

@@ -81,6 +81,7 @@ DEFINE_VARIATION_PARAM(kIPHPreviewsOmniboxUIFeature, "IPH_PreviewsOmniboxUI");
 DEFINE_VARIATION_PARAM(kIPHBookmarkFeature, "IPH_Bookmark");
 DEFINE_VARIATION_PARAM(kIPHIncognitoWindowFeature, "IPH_IncognitoWindow");
 DEFINE_VARIATION_PARAM(kIPHNewTabFeature, "IPH_NewTab");
+DEFINE_VARIATION_PARAM(kIPHReopenTabFeature, "IPH_ReopenTab");
 #endif  // BUILDFLAG(ENABLE_DESKTOP_IN_PRODUCT_HELP)
 #if defined(OS_IOS)
 DEFINE_VARIATION_PARAM(kIPHBottomToolbarTipFeature, "IPH_BottomToolbarTip");
@@ -124,6 +125,7 @@ constexpr flags_ui::FeatureEntry::FeatureVariation
         VARIATION_ENTRY(kIPHBookmarkFeature),
         VARIATION_ENTRY(kIPHIncognitoWindowFeature),
         VARIATION_ENTRY(kIPHNewTabFeature),
+        VARIATION_ENTRY(kIPHReopenTabFeature),
 #elif defined(OS_IOS)
         VARIATION_ENTRY(kIPHBottomToolbarTipFeature),
         VARIATION_ENTRY(kIPHLongPressToolbarTipFeature),