Add field trial under enable-tab-grid-layout flag for M86 FastPath

This CL adds the enable_launch_polish field trial and utility method for
M86 FastPath.

The utility method is added, so we can run the formal equivalence
checking tool.

Bug: 1124835
Change-Id: I7bb0152ebc4138f1023e8a8fe9715cf4524b5a1b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2392773
Commit-Queue: Mei Liang <meiliang@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Reviewed-by: Yue Zhang <yuezhanggg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#804490}

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabUiFeatureUtilities.java

@@ -57,6 +57,11 @@ public class TabUiFeatureUtilities {
             new BooleanCachedFieldTrialParameter(
                     ChromeFeatureList.TAB_GRID_LAYOUT_ANDROID, SEARCH_CHIP_ADAPTIVE_PARAM, false);
 
+    private static final String LAUNCH_POLISH_PARAM = "enable_launch_polish";
+    public static final BooleanCachedFieldTrialParameter ENABLE_LAUNCH_POLISH =
+            new BooleanCachedFieldTrialParameter(
+                    ChromeFeatureList.TAB_GRID_LAYOUT_ANDROID, LAUNCH_POLISH_PARAM, false);
+
     // Field trial parameter for the minimum Android SDK version to enable zooming animation.
     private static final String MIN_SDK_PARAM = "zooming-min-sdk-version";
     public static final IntCachedFieldTrialParameter ZOOMING_MIN_SDK =
@@ -183,4 +188,11 @@ public static boolean supportInstantStart(boolean isTablet) {
                 && CachedFeatureFlags.isEnabled(ChromeFeatureList.INSTANT_START) && !isTablet
                 && !StartSurfaceConfiguration.isStartSurfaceStackTabSwitcherEnabled();
     }
+
+    /**
+     * @return Whether the Grid/Group launch polish is enabled.
+     */
+    public static boolean isLaunchPolishEnabled() {
+        return ENABLE_LAUNCH_POLISH.getValue();
+    }
 }

chrome/android/java/src/org/chromium/chrome/browser/app/flags/ChromeCachedFlags.java

@@ -96,6 +96,7 @@ public void cacheNativeFlags() {
                 StartSurfaceConfiguration.TRENDY_FAILURE_MIN_PERIOD_MS,
                 StartSurfaceConfiguration.TRENDY_SUCCESS_MIN_PERIOD_MS,
                 TabContentManager.ALLOW_TO_REFETCH_TAB_THUMBNAIL_VARIATION,
+                TabUiFeatureUtilities.ENABLE_LAUNCH_POLISH,
                 TabUiFeatureUtilities.ENABLE_SEARCH_CHIP,
                 TabUiFeatureUtilities.ENABLE_SEARCH_CHIP_ADAPTIVE,
                 TabUiFeatureUtilities.ZOOMING_MIN_MEMORY,

chrome/browser/about_flags.cc

@@ -1614,7 +1614,8 @@ const FeatureEntry::FeatureParam kTabGridLayoutAndroid_NewTabTile[] = {
 const FeatureEntry::FeatureParam kTabGridLayoutAndroid_TallNTV[] = {
     {"thumbnail_aspect_ratio", "0.85"},
     {"allow_to_refetch", "true"},
-    {"tab_grid_layout_android_new_tab", "NewTabVariation"}};
+    {"tab_grid_layout_android_new_tab", "NewTabVariation"},
+    {"enable_launch_polish", "true"}};
 
 const FeatureEntry::FeatureParam kTabGridLayoutAndroid_SearchChip[] = {
     {"enable_search_term_chip", "true"}};