Ensures the first browser in each interactive_ui_test is in the foreground

chrome/test/base/in_process_browser_test.cc

Index: chrome/test/base/in_process_browser_test.cc
diff --git a/chrome/test/base/in_process_browser_test.cc b/chrome/test/base/in_process_browser_test.cc
index 354e5fcb47146cda4f2387516fe0c5ad540197ca..2c82ab0033a69fc650ad4e96c2b2a065f85f255d 100644
--- a/chrome/test/base/in_process_browser_test.cc
+++ b/chrome/test/base/in_process_browser_test.cc
@@ -93,6 +93,10 @@ const char kBrowserTestType[] = "browser";
 
 }  // namespace
 
+// static
+InProcessBrowserTest::SetUpBrowserFunction*
+    InProcessBrowserTest::global_browser_set_up_function_ = nullptr;
+
 // Library used for testing accessibility.
 const base::FilePath::CharType kAXSTesting[] =
     FILE_PATH_LITERAL("third_party/accessibility-audit/axs_testing.js");
@@ -535,6 +539,9 @@ void InProcessBrowserTest::RunTestOnMainThreadLoop() {
   // enable/disable the accessibility audit.
   run_accessibility_checks_for_test_case_ = false;
 
+  if (browser_ && global_browser_set_up_function_)
+    ASSERT_TRUE(global_browser_set_up_function_(browser_));
+
   SetUpOnMainThread();
 #if defined(OS_MACOSX)
   autorelease_pool_->Recycle();