Use default CSP for resource loading in webview (instead of platform app's CSP)

extensions/browser/extensions_browser_client.h

Index: extensions/browser/extensions_browser_client.h
diff --git a/extensions/browser/extensions_browser_client.h b/extensions/browser/extensions_browser_client.h
index d7c02d95a38f57fc2d8a17bc816430fcce7ff931..e3b91b27756dd08661d9af06cbc1cf4cd9fc68f1 100644
--- a/extensions/browser/extensions_browser_client.h
+++ b/extensions/browser/extensions_browser_client.h
@@ -96,6 +96,10 @@ class ExtensionsBrowserClient {
       const extensions::Extension* extension,
       content::BrowserContext* context) const = 0;
 
+  // Returns true if |request| corresponds to a resource request from a
+  // <webview>.
+  virtual bool IsWebViewRequest(net::URLRequest* request) const = 0;
+
   // Returns an URLRequestJob to load an extension resource from the embedder's
   // resource bundle (.pak) files. Returns NULL if the request is not for a
   // resource bundle resource or if the embedder does not support this feature.