Add enable_gpu_service_logging GN argument and about flag.

1. Add enable_gpu_service_logging GN argument. This can be used in
Release builds without dcheck_always_on=true, and allows the
--enable-gpu-service-logging command line argument to work.

2. Add about flag 'Enable gpu service logging' to let non-rooted
devices enable the --enable-gpu-service-logging flag.

Bug: 839769
Change-Id: Ic6fe4d97aaa6deb51b1f4d30ac4e7aeeaf8b4700
Reviewed-on: https://chromium-review.googlesource.com/c/1401616
Commit-Queue: vikas soni <[email protected]>
Reviewed-by: Avi Drissman <[email protected]>
Reviewed-by: Kenneth Russell <[email protected]>
Cr-Commit-Position: refs/heads/master@{#622252}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 07e99b8..6031f3f8 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -4286,6 +4286,10 @@
      kOsAll,
      FEATURE_VALUE_TYPE(
          autofill::features::kAutocompleteRetentionPolicyEnabled)},
+    {"enable-gpu-service-logging",
+     flag_descriptions::kEnableGpuServiceLoggingName,
+     flag_descriptions::kEnableGpuServiceLoggingDescription, kOsAll,
+     SINGLE_VALUE_TYPE(switches::kEnableGPUServiceLogging)},
 };
 
 class FlagsStateSingleton {