Make components_browsertests initialize the ShellMainDelegate as a browsertest.

Bug: 1066264
Change-Id: I8e0949be2a74e39cddab6887d077af2b90bfb484
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2128980
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755002}

components/test/android/browsertests_apk/components_browser_tests_jni_onload.cc

@@ -27,6 +27,7 @@ JNI_EXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
         return std::make_unique<content::NestedMessagePumpAndroid>();
       });
 
-  content::SetContentMainDelegate(new content::ShellMainDelegate());
+  content::SetContentMainDelegate(
+      new content::ShellMainDelegate(/*is_browsertest=*/true));
   return JNI_VERSION_1_4;
 }