Add the ability to override WebContentsBindingSet binders for testing

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 9978654a34422637c3204e7771c975e740d3b29c..d9af4167886aa600f5f10b87f18632f8a29b8041 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -37,6 +37,7 @@
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_binding_set.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/page_importance_signals.h"
 #include "content/public/common/renderer_preferences.h"
@@ -79,7 +80,6 @@ class TestWebContents;
 class TextInputManager;
 class WakeLockServiceContext;
 class WebContentsAudioMuter;
-class WebContentsBindingSet;
 class WebContentsDelegate;
 class WebContentsImpl;
 class WebContentsView;
@@ -262,6 +262,18 @@ class CONTENT_EXPORT WebContentsImpl
   base::Closure AddBindingSet(const std::string& interface_name,
                               WebContentsBindingSet* binding_set);
 
+  // Overrides the incoming Channel-associated interface request handler for
+  // interfaces registered with this WebContents via a WebContentsBindingSet.
+  // |binder| will live until either the binder is overridden again or the
+  // WebContents is destroyed.
+  template <typename Interface>
+  void OverrideBinderForTesting(
+      std::unique_ptr<WebContentsBindingSet::Binder> binder) {
+    auto it = binding_sets_.find(Interface::Name_);
+    DCHECK(it != binding_sets_.end());
+    it->second->SetBinderForTesting(std::move(binder));
+  }
+
   // WebContents ------------------------------------------------------
   WebContentsDelegate* GetDelegate() override;
   void SetDelegate(WebContentsDelegate* delegate) override;