fix bug where translate infobar gets stuck at "Loading..." between switching tabs.

- problem happened because infobars are destructed when switching between tabs, only the delegates persist.  without the infobar to receive the PAGE_TRANSLATED notification to update the translate state, the infobar gets stuck at translating state when user switches back to the associated tab.
- fix was to update the state in the infobar delegate on receiving PAGE_TRANSLATE notification so that when a new translate infobar is created, its visual display will reflect the updated after-translate state.

BUG=36895
TEST=verify per bug report.

Review URL: http://codereview.chromium.org/660187

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@40135 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 9 insertions, 3 deletions

diff --git a/chrome/browser/translate/translate_infobars_delegates.cc b/chrome/browser/translate/translate_infobars_delegates.cc
index 2aad0b4..8107f4f 100644
--- a/chrome/browser/translate/translate_infobars_delegates.cc
+++ b/chrome/browser/translate/translate_infobars_delegates.cc
@@ -97,6 +97,8 @@ void TranslateInfoBarDelegate::GetAvailableTargetLanguages(
 }
 
 void TranslateInfoBarDelegate::Translate() {
+  if (state_ == kBeforeTranslate)
+    UpdateState(kTranslating);
   tab_contents_->TranslatePage(original_lang_code(), target_lang_code());
 }
 
diff --git a/chrome/browser/translate/translate_manager.cc b/chrome/browser/translate/translate_manager.cc
index 8c90bdf..9435786 100644
--- a/chrome/browser/translate/translate_manager.cc
+++ b/chrome/browser/translate/translate_manager.cc
@@ -75,13 +75,17 @@ void TranslateManager::Observe(NotificationType type,
     }
     case NotificationType::PAGE_TRANSLATED: {
       // Only add translate infobar if it doesn't exist; if it already exists,
-      // it would have received the same notification and acted accordingly.
+      // just update the state, the actual infobar would have received the same
+      //  notification and update the visual display accordingly.
       TabContents* tab = Source<TabContents>(source).ptr();
       int i;
       for (i = 0; i < tab->infobar_delegate_count(); ++i) {
-        InfoBarDelegate* info_bar = tab->GetInfoBarDelegateAt(i);
-        if (info_bar->AsTranslateInfoBarDelegate())
+        TranslateInfoBarDelegate* info_bar =
+            tab->GetInfoBarDelegateAt(i)->AsTranslateInfoBarDelegate();
+        if (info_bar) {
+          info_bar->UpdateState(TranslateInfoBarDelegate::kAfterTranslate);
           break;
+        }
       }
       if (i == tab->infobar_delegate_count()) {
         NavigationEntry* entry = tab->controller().GetActiveEntry();