Override IsRedirectResponse in extension protocols

The default URLFileRequestJob::IsRedirectResponse implementation is incorrect
for URLRequestExtensionJob (chrome-extension:-scheme) and ExtensionResourcesJob (chrome-extension-resource:-scheme).

BUG=388852,424961

Review URL: https://codereview.chromium.org/650453003

Cr-Commit-Position: refs/heads/master@{#300329}

chrome/browser/extensions/extension_resource_protocols.cc

@@ -35,6 +35,9 @@ class ExtensionResourcesJob : public net::URLRequestFileJob {
 
   virtual void Start() override;
 
+  virtual bool IsRedirectResponse(GURL* location,
+                                  int* http_status_code) override;
+
  protected:
   virtual ~ExtensionResourcesJob() {}
 
@@ -57,6 +60,11 @@ void ExtensionResourcesJob::Start() {
           weak_ptr_factory_.GetWeakPtr()));
 }
 
+bool ExtensionResourcesJob::IsRedirectResponse(GURL* location,
+                                               int* http_status_code) {
+  return false;
+}
+
 void ExtensionResourcesJob::ResolvePathDone(
     const base::FilePath& resolved_path) {
   DCHECK(thread_checker_.CalledOnValidThread());

extensions/browser/extension_protocols.cc

@@ -220,6 +220,11 @@ class URLRequestExtensionJob : public net::URLRequestFileJob {
     DCHECK(posted);
   }
 
+  virtual bool IsRedirectResponse(GURL* location,
+                                  int* http_status_code) override {
+    return false;
+  }
+
   virtual void SetExtraRequestHeaders(
       const net::HttpRequestHeaders& headers) override {
     // TODO(asargent) - we'll need to add proper support for range headers.