Add a new gyp flag: fieldtrial_testing_like_official_build

When set to 1, this will NOT activate the field trial test specified
in the fieldtrial_testing_config_*.json.  This gives Chromium
packagers the flexibility to disable field trial testing config for
their package as we have on our Google Chrome build.

BUG=515686

Review URL: https://codereview.chromium.org/1266113002

Cr-Commit-Position: refs/heads/master@{#341845}

4 files changed, 19 insertions, 2 deletions

diff --git a/build/common.gypi b/build/common.gypi
index 5915055..fe2c57a 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -368,6 +368,11 @@
       # Note: this setting is ignored if buildtype=="Official".
       'tracing_like_official_build%': 0,
 
+      # Set to 1 to make a build that disables activation of field trial tests
+      # specified in testing/variations/fieldtrial_testing_config_*.json.
+      # Note: this setting is ignored if branding=="Chrome".
+      'fieldtrial_testing_like_official_build%': 0,
+
       # Disable image loader component extension by default.
       'image_loader_extension%': 0,
 
@@ -1142,6 +1147,7 @@
     'win_z7%': '<(win_z7)',
     'dcheck_always_on%': '<(dcheck_always_on)',
     'tracing_like_official_build%': '<(tracing_like_official_build)',
+    'fieldtrial_testing_like_official_build%': '<(fieldtrial_testing_like_official_build)',
     'arm_version%': '<(arm_version)',
     'arm_neon%': '<(arm_neon)',
     'arm_neon_optional%': '<(arm_neon_optional)',
@@ -2857,6 +2863,9 @@
       ['tracing_like_official_build!=0', {
         'defines': ['TRACING_IS_OFFICIAL_BUILD=1'],
       }],  # tracing_like_official_build!=0
+      ['fieldtrial_testing_like_official_build==0 and branding!="Chrome"', {
+        'defines': ['FIELDTRIAL_TESTING_ENABLED'],
+      }],  # fieldtrial_testing_like_official_build==0 and branding!="Chrome"
       ['OS=="win"', {
         'defines': ['NO_TCMALLOC'],
         'conditions': [
diff --git a/build/config/BUILD.gn b/build/config/BUILD.gn
index b6b9520..75fa3aa 100644
--- a/build/config/BUILD.gn
+++ b/build/config/BUILD.gn
@@ -289,6 +289,9 @@ config("feature_flags") {
       "MEMORY_SANITIZER_INITIAL_SIZE",
     ]
   }
+  if (!fieldtrial_testing_like_official_build && !is_chrome_branded) {
+    defines += [ "FIELDTRIAL_TESTING_ENABLED" ]
+  }
 }
 
 # Debug/release ----------------------------------------------------------------
diff --git a/build/config/features.gni b/build/config/features.gni
index 3a34bd2..6d8f25a 100644
--- a/build/config/features.gni
+++ b/build/config/features.gni
@@ -110,6 +110,11 @@ declare_args() {
   } else {
     safe_browsing_mode = 1
   }
+
+  # Set to true make a build that disables activation of field trial tests
+  # specified in testing/variations/fieldtrial_testing_config_*.json.
+  # Note: this setting is ignored if is_chrome_branded.
+  fieldtrial_testing_like_official_build = is_chrome_branded
 }
 
 # Additional dependent variables -----------------------------------------------
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index cb5e28f..669b84e 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -634,12 +634,12 @@ void ChromeBrowserMainParts::SetupMetricsAndFieldTrials() {
                   << " list specified.";
   }
 
-#if !defined(GOOGLE_CHROME_BUILD)
+#if defined(FIELDTRIAL_TESTING_ENABLED)
   if (!command_line->HasSwitch(switches::kDisableFieldTrialTestingConfig) &&
       !command_line->HasSwitch(switches::kForceFieldTrials) &&
       !command_line->HasSwitch(switches::kVariationsServerURL))
     chrome_variations::AssociateDefaultFieldTrialConfig();
-#endif  // !defined(GOOGLE_CHROME_BUILD)
+#endif  // defined(FIELDTRIAL_TESTING_ENABLED)
 
   if (command_line->HasSwitch(switches::kForceVariationIds)) {
     // Create default variation ids which will always be included in the