Disable storing cookies from URLFetchers that run with a profile's cookie jar.

chrome/browser/extensions/webstore_install_helper.cc

Index: chrome/browser/extensions/webstore_install_helper.cc
diff --git a/chrome/browser/extensions/webstore_install_helper.cc b/chrome/browser/extensions/webstore_install_helper.cc
index 979173caf03986bba6d85b6b33d026ef5434d584..d5184ed870a543d054c448e2946f31640d13872d 100644
--- a/chrome/browser/extensions/webstore_install_helper.cc
+++ b/chrome/browser/extensions/webstore_install_helper.cc
@@ -12,6 +12,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/utility_process_host.h"
 #include "content/public/common/url_fetcher.h"
+#include "net/base/load_flags.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "net/url_request/url_request_status.h"
 
@@ -60,6 +61,7 @@ void WebstoreInstallHelper::Start() {
     url_fetcher_.reset(content::URLFetcher::Create(
         icon_url_, content::URLFetcher::GET, this));
     url_fetcher_->SetRequestContext(context_getter_);
+    url_fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES);
 
     url_fetcher_->Start();
     // We'll get called back in OnURLFetchComplete.