Add the scheme chrome-distiller:// and hook up data source.

content/browser/browser_url_handler_impl.cc

Index: content/browser/browser_url_handler_impl.cc
diff --git a/content/browser/browser_url_handler_impl.cc b/content/browser/browser_url_handler_impl.cc
index fb657c0547b9c87e969cb4293e07878d6bbc6afd..5ac3bae2c9517ad474ec435f407420afb49b37a9 100644
--- a/content/browser/browser_url_handler_impl.cc
+++ b/content/browser/browser_url_handler_impl.cc
@@ -37,6 +37,20 @@ static bool HandleViewSource(GURL* url, BrowserContext* browser_context) {
       }
     }
 
+    // If none of the default allowed schemes match, try with additional schemes
+    // from the ContentClient.
+    if (!is_sub_scheme_allowed) {
+      std::vector<std::string> additional_schemes;
+      GetContentClient()->browser()->GetAdditionalSchemesForViewSource(

[jam, 2014/01/24 22:07:55]

actually, now that I think about it some more, it seems reasonable that we call
GetAdditionalWebUISchemes here and then we don't need
GetAdditionalSchemesForViewSource at all. then you can create a vector and stick
allowed_sub_schemes in them and also the result of GetAdditionalWebUISchemes, so
that this small for loop below doesn't need to be duplicated as well

[nyquist, 2014/01/25 00:40:38]

Done.

One note: this adds chrome::kChromeSearchScheme to the list of schemes for which
view-source is allowed.

+          &additional_schemes);
+      for (size_t i = 0; i < additional_schemes.size(); ++i) {
+        if (url->SchemeIs(additional_schemes[i].c_str())) {
+          is_sub_scheme_allowed = true;
+          break;
+        }
+      }
+    }
+
     if (!is_sub_scheme_allowed) {
       *url = GURL(kAboutBlankURL);
       return false;