Update field trial name for StartSurface

Before this change, after changing StartSurface variation with a local
debug build, Chrome crashes during restart with the following error:

chromium: [FATAL:feature_list.cc(185)] Check failed:!Contains(overrides_,
feature_name) || !overrides_.find(feature_name)->second.field_trial.
Feature StartSurfaceAndroid has conflicting field trial overrides:
StartSurfaceAndroid / ChromeStart

This CL fixes the crash, and updates the log message to be more specific.

Change-Id: I0f4dedb43c9fd12133e363375a8de5a0cb3eb3e8
Bug: 1059081
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2083855
Commit-Queue: Mei Liang <[email protected]>
Reviewed-by: Ilya Sherman <[email protected]>
Reviewed-by: Ganggui Tang <[email protected]>
Reviewed-by: Wei-Yin Chen (陳威尹) <[email protected]>
Cr-Commit-Position: refs/heads/master@{#747539}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 0e42401..db99c91 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -3407,7 +3407,7 @@
      flag_descriptions::kStartSurfaceAndroidDescription, kOsAndroid,
      FEATURE_WITH_PARAMS_VALUE_TYPE(chrome::android::kStartSurfaceAndroid,
                                     kStartSurfaceAndroidVariations,
-                                    "StartSurfaceAndroid")},
+                                    "ChromeStart")},
 
     {"enable-close-tab-suggestions",
      flag_descriptions::kCloseTabSuggestionsName,
@@ -3446,7 +3446,7 @@
      flag_descriptions::kTabSwitcherOnReturnDescription, kOsAndroid,
      FEATURE_WITH_PARAMS_VALUE_TYPE(chrome::android::kTabSwitcherOnReturn,
                                     kTabSwitcherOnReturnVariations,
-                                    "TabSwitcherOnReturn")},
+                                    "ChromeStart")},
 
     {"enable-tab-to-gts-animation",
      flag_descriptions::kTabToGTSAnimationAndroidName,