Returning Corresponding Error Message when their is error in OpenTab.

chrome/browser/extensions/extension_tab_util.cc

Index: chrome/browser/extensions/extension_tab_util.cc
diff --git a/chrome/browser/extensions/extension_tab_util.cc b/chrome/browser/extensions/extension_tab_util.cc
index 706f41e009130deadd8baeca5763a635f234adb9..393b8d3f651d7ac08b15857cf5bb13ac57141272 100644
--- a/chrome/browser/extensions/extension_tab_util.cc
+++ b/chrome/browser/extensions/extension_tab_util.cc
@@ -143,7 +143,8 @@ base::DictionaryValue* ExtensionTabUtil::OpenTab(
                                         browser->host_desktop_type());
 
   if (!browser || !browser->window()) {
-    // TODO(rpaquay): Error message?
+    if (error)
+      *error = keys::kNoCurrentWindowError;
     return NULL;
   }
 
@@ -160,7 +161,10 @@ base::DictionaryValue* ExtensionTabUtil::OpenTab(
                                       NULL,
                                       &opener,
                                       NULL)) {
-      // TODO(rpaquay): Error message?
+      if (error) {
+        *error = ErrorUtils::FormatErrorMessage(
+        keys::kTabNotFoundError, base::IntToString(opener_id));

[Ken Rockot(use gerrit already), 2015/05/08 19:33:09]

nit: This formatting is incorrect. Running 'git cl format' should automate
formatting for you.

[Deepak, 2015/05/09 04:52:25]

Done.

+      }
       return NULL;
     }
   }