Fix for a translate related crasher.

When a page was closed, a pending task on the TranslationHelper was accessing the WebView that would be NULL.

BUG=46584
TEST=None

Review URL: http://codereview.chromium.org/2852005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@49863 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 16 insertions, 4 deletions

diff --git a/chrome/renderer/translate_helper.cc b/chrome/renderer/translate_helper.cc
index 1fea5b7..7caeec4 100644
--- a/chrome/renderer/translate_helper.cc
+++ b/chrome/renderer/translate_helper.cc
@@ -81,7 +81,7 @@ void TranslateHelper::RevertTranslation(int page_id) {
     return;
   }
 
-  WebFrame* main_frame = render_view_->webview()->mainFrame();
+  WebFrame* main_frame = GetMainFrame();
   if (!main_frame)
     return;
 
@@ -213,7 +213,7 @@ void TranslateHelper::CheckTranslateStatus() {
 }
 
 bool TranslateHelper::ExecuteScript(const std::string& script) {
-  WebFrame* main_frame = render_view_->webview()->mainFrame();
+  WebFrame* main_frame = GetMainFrame();
   if (!main_frame)
     return false;
   main_frame->executeScript(WebScriptSource(ASCIIToUTF16(script)));
@@ -223,7 +223,7 @@ bool TranslateHelper::ExecuteScript(const std::string& script) {
 bool TranslateHelper::ExecuteScriptAndGetBoolResult(const std::string& script,
                                                     bool* value) {
   DCHECK(value);
-  WebFrame* main_frame = render_view_->webview()->mainFrame();
+  WebFrame* main_frame = GetMainFrame();
   if (!main_frame)
     return false;
 
@@ -239,7 +239,7 @@ bool TranslateHelper::ExecuteScriptAndGetBoolResult(const std::string& script,
 bool TranslateHelper::ExecuteScriptAndGetStringResult(const std::string& script,
                                                       std::string* value) {
   DCHECK(value);
-  WebFrame* main_frame = render_view_->webview()->mainFrame();
+  WebFrame* main_frame = GetMainFrame();
   if (!main_frame)
     return false;
 
@@ -292,3 +292,15 @@ void TranslateHelper::NotifyBrowserTranslationFailed(
   render_view_->Send(new ViewHostMsg_PageTranslated(
       render_view_->routing_id(), page_id_, source_lang_, target_lang_, error));
 }
+
+WebFrame* TranslateHelper::GetMainFrame() {
+  WebKit::WebView* web_view = render_view_->webview();
+  if (!web_view) {
+    // When the WebView is going away, the render view should have called
+    // CancelPendingTranslation() which should have stopped any pending work, so
+    // that case should not happen.
+    NOTREACHED();
+    return NULL;
+  }
+  return web_view->mainFrame();
+}