Add CastMediaBlocker and BrowserTest

chromecast/browser/test/chromecast_browser_test_helper_default.cc

Index: chromecast/browser/test/chromecast_browser_test_helper_default.cc
diff --git a/chromecast/browser/test/chromecast_browser_test_helper_default.cc b/chromecast/browser/test/chromecast_browser_test_helper_default.cc
index f5aad5f660f31a2b745498d92444ba3d8713f411..8a50925444b7a05a8bbc9c06d16b52cbc59aa428 100644
--- a/chromecast/browser/test/chromecast_browser_test_helper_default.cc
+++ b/chromecast/browser/test/chromecast_browser_test_helper_default.cc
@@ -8,6 +8,7 @@
 #include "chromecast/browser/cast_browser_context.h"
 #include "chromecast/browser/cast_browser_process.h"
 #include "chromecast/browser/cast_content_window.h"
+#include "chromecast/browser/cast_media_blocker.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/test_navigation_observer.h"
@@ -26,6 +27,7 @@ class DefaultHelper : public ChromecastBrowserTestHelper {
     web_contents_ = window_->CreateWebContents(
         CastBrowserProcess::GetInstance()->browser_context());
     window_->CreateWindowTree(web_contents_.get());
+    blocker_.reset(new CastMediaBlocker(web_contents_.get()));
 
     content::WaitForLoadStop(web_contents_.get());
     content::TestNavigationObserver same_tab_observer(web_contents_.get(), 1);
@@ -38,9 +40,14 @@ class DefaultHelper : public ChromecastBrowserTestHelper {
     return web_contents_.get();
   }
 
+  void BlockMediaLoading(bool block) override {
+    blocker_->BlockMediaLoading(block);
+  }
+
  private:
   std::unique_ptr<CastContentWindow> window_;
   std::unique_ptr<content::WebContents> web_contents_;
+  std::unique_ptr<CastMediaBlocker> blocker_;
 };
 
 }  // namespace