Refactor the way that TestApi works so that it is actually useful.

scripts/slave/recipe_modules/chromium_android/config.expected/repo-internal-from-url-bob_dot_org-internal.json

Index: scripts/slave/recipe_modules/chromium_android/config.expected/repo-internal-from-url-bob_dot_org-internal.json
diff --git a/scripts/slave/recipe_modules/chromium_android/config.expected/repo-internal-from-url-bob_dot_org-internal.json b/scripts/slave/recipe_modules/chromium_android/config.expected/repo-internal-from-url-bob_dot_org-internal.json
index 05ad5ec20985948f7fd78a4284ec8836bcddec96..f01302ac5362e09511eba136dc9e23ec587613da 100644
--- a/scripts/slave/recipe_modules/chromium_android/config.expected/repo-internal-from-url-bob_dot_org-internal.json
+++ b/scripts/slave/recipe_modules/chromium_android/config.expected/repo-internal-from-url-bob_dot_org-internal.json
@@ -1,6 +1,5 @@
 {
   "clang_builder": {
-    "custom_vars": {}, 
     "extra_env": {}, 
     "run_checkdeps": true, 
     "run_findbugs": true, 
@@ -8,7 +7,6 @@
     "target_arch": ""
   }, 
   "component_builder": {
-    "custom_vars": {}, 
     "extra_env": {}, 
     "run_checkdeps": false, 
     "run_findbugs": false, 
@@ -16,7 +14,6 @@
     "target_arch": ""
   }, 
   "klp_builder": {
-    "custom_vars": {}, 
     "extra_env": {
       "ANDROID_SDK_BUILD_TOOLS_VERSION": "android-KeyLimePie", 
       "ANDROID_SDK_ROOT": [
@@ -32,7 +29,6 @@
     "target_arch": ""
   }, 
   "main_builder": {
-    "custom_vars": {}, 
     "extra_env": {}, 
     "run_checkdeps": false, 
     "run_findbugs": false, 
@@ -40,7 +36,6 @@
     "target_arch": ""
   }, 
   "try_builder": {
-    "custom_vars": {}, 
     "extra_env": {}, 
     "run_checkdeps": false, 
     "run_findbugs": true, 
@@ -48,7 +43,6 @@
     "target_arch": ""
   }, 
   "x86_builder": {
-    "custom_vars": {}, 
     "extra_env": {}, 
     "run_checkdeps": false, 
     "run_findbugs": false,