headless: Make it possible to configure an HTTP proxy

headless/test/headless_browser_test.h

Index: headless/test/headless_browser_test.h
diff --git a/headless/test/headless_browser_test.h b/headless/test/headless_browser_test.h
index 9b5623495197854c9d83bae1d933184d13df89c2..f46fb90ba60c74f6867b391d9008f3da5d4bf88c 100644
--- a/headless/test/headless_browser_test.h
+++ b/headless/test/headless_browser_test.h
@@ -6,9 +6,10 @@
 #define HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_
 
 #include "content/public/test/browser_test_base.h"
+#include "headless/public/headless_browser.h"
 
 namespace headless {
-class HeadlessBrowser;
+class HeadlessWebContents;
 
 // Base class for tests which require a full instance of the headless browser.
 class HeadlessBrowserTest : public content::BrowserTestBase {
@@ -21,6 +22,15 @@ class HeadlessBrowserTest : public content::BrowserTestBase {
   void SetUpOnMainThread() override;
   void TearDownOnMainThread() override;
 
+  // Customize the options used in this test. Note that options which take
+  // effect before the message loop has been started (e.g., custom message
+  // pumps) cannot be set via this method.
+  void SetBrowserOptions(const HeadlessBrowser::Options& options);
+
+  // Navigate to |url| and wait for the document load to complete.
+  bool NavigateAndWaitForLoad(HeadlessWebContents* web_contents,
+                              const GURL& url);
+
  protected:
   // Returns the browser for the test.
   HeadlessBrowser* browser() const;