Add delegate to install web_contents helpers for MimeHandlerView.

chrome/browser/extensions/api/chrome_extensions_api_client.h

Index: chrome/browser/extensions/api/chrome_extensions_api_client.h
diff --git a/chrome/browser/extensions/api/chrome_extensions_api_client.h b/chrome/browser/extensions/api/chrome_extensions_api_client.h
index e7bc28c361c8789d352c158154a1f80bee4b6031..eefc2eca9648fe6eacf115479df1c200110bbb67 100644
--- a/chrome/browser/extensions/api/chrome_extensions_api_client.h
+++ b/chrome/browser/extensions/api/chrome_extensions_api_client.h
@@ -10,6 +10,8 @@
 
 namespace extensions {
 
+class MimeHandlerViewGuest;

[Ken Rockot(use gerrit already), 2014/09/09 23:33:08]

nit: I would argue that this is redundant since you're implementing an interface
that must have already declared its existence.

[lazyboy, 2014/09/09 23:44:35]

Right, removed.
Done.

+
 // Extra support for extensions APIs in Chrome.
 class ChromeExtensionsAPIClient : public ExtensionsAPIClient {
  public:
@@ -24,6 +26,9 @@ class ChromeExtensionsAPIClient : public ExtensionsAPIClient {
       std::map<settings_namespace::Namespace, ValueStoreCache*>* caches)
       OVERRIDE;
   virtual AppViewGuestDelegate* CreateAppViewGuestDelegate() const OVERRIDE;
+  virtual scoped_ptr<MimeHandlerViewGuestDelegate>
+      CreateMimeHandlerViewGuestDelegate(
+          MimeHandlerViewGuest* guest) const OVERRIDE;
   virtual WebViewGuestDelegate* CreateWebViewGuestDelegate(
       WebViewGuest* web_view_guest) const OVERRIDE;
   virtual WebViewPermissionHelperDelegate*