Enable isolate on Linux release builder.

scripts/slave/recipe_modules/chromium_tests/api.py

Index: scripts/slave/recipe_modules/chromium_tests/api.py
diff --git a/scripts/slave/recipe_modules/chromium_tests/api.py b/scripts/slave/recipe_modules/chromium_tests/api.py
index 4c95fc617c9f40069e06c48bb6c75054aeca9858..82ec90773fd9801e9dd6d23bb6ffb6ab986e6571 100644
--- a/scripts/slave/recipe_modules/chromium_tests/api.py
+++ b/scripts/slave/recipe_modules/chromium_tests/api.py
@@ -221,13 +221,15 @@ class ChromiumTestsApi(recipe_api.RecipeApi):
 
     if bot_type in ['builder', 'builder_tester']:
       compile_targets = set(bot_config.get('compile_targets', []))
-      for test in tests:
-        compile_targets.update(test.compile_targets(self.m))
+      tests_including_triggered = tests[:]
       for loop_buildername, builder_dict in master_dict.get(
           'builders', {}).iteritems():
         if builder_dict.get('parent_buildername') == buildername:
           for test in builder_dict.get('tests', []):
-            compile_targets.update(test.compile_targets(self.m))
+            tests_including_triggered.append(test)
+
+      for t in tests_including_triggered:
+        compile_targets.update(t.compile_targets(self.m))
 
       self.m.chromium.compile(targets=sorted(compile_targets))
       self.m.chromium.checkdeps()
@@ -236,12 +238,10 @@ class ChromiumTestsApi(recipe_api.RecipeApi):
         self.m.chromium_android.check_webview_licenses()
         self.m.chromium_android.findbugs()
 
-      has_swarming_tests = any(t.uses_swarming for t in tests)
-      if bot_config.get('use_isolate'):
-        self.m.isolate.find_isolated_tests(self.m.chromium.output_dir)
-      # TODO(phajdan.jr): Always use the below codepath once fully tested.
-      elif has_swarming_tests:
-        isolated_targets = [t.name for t in tests if t.uses_swarming]
+      isolated_targets = [
+        t.name for t in tests_including_triggered if t.uses_swarming
+      ]
+      if isolated_targets:
         self.m.isolate.find_isolated_tests(
             self.m.chromium.output_dir, targets=list(set(isolated_targets)))