Implement chrome://network-errors for direct access to network error interstitials

content/browser/webui/url_data_manager_backend.cc

Index: content/browser/webui/url_data_manager_backend.cc
diff --git a/content/browser/webui/url_data_manager_backend.cc b/content/browser/webui/url_data_manager_backend.cc
index ac346dda7ca827cb786eabfff9963a3d313a1310..e16b219a5f34fec90346dc5e85e036c6cb295359 100644
--- a/content/browser/webui/url_data_manager_backend.cc
+++ b/content/browser/webui/url_data_manager_backend.cc
@@ -18,6 +18,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
@@ -39,10 +40,13 @@
 #include "net/base/net_errors.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_status_code.h"
+#include "net/log/net_log_util.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_error_job.h"
 #include "net/url_request/url_request_job.h"
 #include "net/url_request/url_request_job_factory.h"
+
 #include "url/url_util.h"
 
 namespace content {
@@ -53,7 +57,7 @@ const char kChromeURLContentSecurityPolicyHeaderBase[] =
     "Content-Security-Policy: script-src chrome://resources 'self'";
 
 const char kChromeURLXFrameOptionsHeader[] = "X-Frame-Options: DENY";
-
+static const char kNetworkErrorKey[] = "netError";
 const int kNoRenderProcessId = -1;
 
 bool SchemeIsInSchemes(const std::string& scheme,
@@ -462,6 +466,27 @@ void GetMimeTypeOnUI(URLDataSourceImpl* source,
 }  // namespace
 
 namespace {
+bool IsValidNetworkErrorCode(int error_code) {
+  scoped_ptr<base::DictionaryValue> error_codes = net::GetNetConstants();
+  const base::DictionaryValue* net_error_codes_dict = nullptr;
+
+  for (base::DictionaryValue::Iterator itr(*error_codes); !itr.IsAtEnd();
+           itr.Advance()) {
+    if (itr.key() == kNetworkErrorKey) {
+      itr.value().GetAsDictionary(&net_error_codes_dict);
+      break;
+    }
+  }
+
+  for (base::DictionaryValue::Iterator itr(*net_error_codes_dict);
+           !itr.IsAtEnd(); itr.Advance()) {
+    int net_error_code;
+    itr.value().GetAsInteger(&net_error_code);
+    if (error_code == net_error_code)
+      return true;
+  }
+  return false;
+}
 
 class ChromeProtocolHandler
     : public net::URLRequestJobFactory::ProtocolHandler {
@@ -507,6 +532,24 @@ class ChromeProtocolHandler
       return new HistogramInternalsRequestJob(request, network_delegate);
     }
 
+    // Check for chrome://network-error/, which uses its own job type.
+    if (request->url().SchemeIs(kChromeUIScheme) &&
+        request->url().host() == kChromeUINetworkErrorHost) {
+      // Get the error code passed in via the request URL path.
+      std::basic_string<char> error_code_string =
+          request->url().path().substr(1, std::string::npos);

[Dan Beam, 2015/12/01 04:24:17]

this is equivalent to substr(1), I believe

[edwardjung, 2015/12/01 12:30:08]

Yep, confirmed.

+
+      int error_code;
+      if (base::StringToInt(error_code_string, &error_code)) {
+        // Check for a valid error code.
+        if (IsValidNetworkErrorCode(error_code) &&
+            error_code != net::Error::ERR_IO_PENDING) {
+          return new net::URLRequestErrorJob(request, network_delegate,
+                                             error_code);
+        }
+      }
+    }
+
     // Fall back to using a custom handler
     return new URLRequestChromeJob(
         request, network_delegate,