Add viewing of error messages from Keystone upon self-update failure.

chrome/browser/ui/webui/help/version_updater_mac.mm

Index: chrome/browser/ui/webui/help/version_updater_mac.mm
diff --git a/chrome/browser/ui/webui/help/version_updater_mac.mm b/chrome/browser/ui/webui/help/version_updater_mac.mm
index be9c08fae51df9624654a2f48ced5f131d66cfcf..a96c0bf6246f6084220ea6bd1546d5f0c839c923 100644
--- a/chrome/browser/ui/webui/help/version_updater_mac.mm
+++ b/chrome/browser/ui/webui/help/version_updater_mac.mm
@@ -6,11 +6,15 @@
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/logging.h"
+#include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #import "chrome/browser/mac/keystone_glue.h"
 #include "chrome/browser/obsolete_system/obsolete_system.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
+#include "net/base/escape.h"
 #include "ui/base/l10n/l10n_util.h"
 
 // KeystoneObserver is a simple notification observer for Keystone status
@@ -132,6 +136,8 @@ void VersionUpdaterMac::RelaunchBrowser() const {
 void VersionUpdaterMac::UpdateStatus(NSDictionary* dictionary) {
   AutoupdateStatus keystone_status = static_cast<AutoupdateStatus>(
       [[dictionary objectForKey:kAutoupdateStatusStatus] intValue]);
+  const char* keystone_errors_utf8 =
+      [[dictionary objectForKey:kAutoupdateStatusErrorMessages] UTF8String];

[Mark Mentovai, 2016/03/23 15:52:04]

Use base::SysNSStringToUTF8 instead, to get a std::string. That will handle
embedded NULs more correctly. It’ll avoid the need to call strlen() below, and
since EscapeForHTML() already requires that a std::string be converted, there’s
zero savings in doing any work on this const char*.

[Ryan Myers (chromium), 2016/03/23 22:29:38]

Done.

 
   bool enable_promote_button = true;
   base::string16 message;
@@ -211,6 +217,25 @@ void VersionUpdaterMac::UpdateStatus(NSDictionary* dictionary) {
       NOTREACHED();
       return;
   }
+
+  // If there are any specific error messages being passed along by Keystone,
+  // log them, and include them in a <pre> block if we're showing an error.
+  if (keystone_errors_utf8 && strlen(keystone_errors_utf8)) {
+    VLOG(1) << "Keystone stderr: " << keystone_errors_utf8;
+
+    if (!message.empty()) {
+      // TODO: Should we localize the "Error details" string?  If so, get the

[Mark Mentovai, 2016/03/23 15:52:04]

Yes. All of these strings should be localized.

Even if the strings we get back from Keystone aren’t always localized, all of
our own user-visible strings must be.

[Ryan Myers (chromium), 2016/03/23 22:29:38]

Done.

+      // string translated and into GRD, then replace this StringPrintf call
+      // with a call to l10n_util::GetStringFUTF16(IDS_KEYSTONE_ERROR_DETAILS).
+      std::string escaped_keystone_errors_utf8 =
+          net::EscapeForHTML(keystone_errors_utf8);
+      std::string formatted_errors =
+          base::StringPrintf("<br/><br/>Error details:<br/><pre>%s</pre>",

[Mark Mentovai, 2016/03/23 15:52:04]

You can build this up with string +ing, probably no good reason to bring
StringPrintf into it.

[Ryan Myers (chromium), 2016/03/23 22:29:38]

Done.

+                             escaped_keystone_errors_utf8.c_str());
+      message += base::UTF8ToUTF16(formatted_errors.c_str());
+    }
+  }
+
   if (!status_callback_.is_null())
     status_callback_.Run(status, 0, message);