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

3 files changed, 27 insertions, 4 deletions

diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index 5a43efe..b99adcd 100755
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -2190,6 +2190,10 @@ void RenderView::show(WebNavigationPolicy policy) {
 }
 
 void RenderView::closeWidgetSoon() {
+  // Cancel pending translations so that the translate_helper_ does not attempt
+  // to access the WebView.
+  translate_helper_.CancelPendingTranslation();
+
   if (script_can_close_)
     RenderWidget::closeWidgetSoon();
 }
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();
+}
diff --git a/chrome/renderer/translate_helper.h b/chrome/renderer/translate_helper.h
index 8b55e8a..979f0f1 100644
--- a/chrome/renderer/translate_helper.h
+++ b/chrome/renderer/translate_helper.h
@@ -11,6 +11,9 @@
 #include "chrome/common/translate_errors.h"
 
 class RenderView;
+namespace WebKit {
+class WebFrame;
+}
 
 // This class deals with page translation.
 // There is one TranslateHelper per RenderView.
@@ -99,6 +102,10 @@ class TranslateHelper {
   // with |error|.
   void NotifyBrowserTranslationFailed(TranslateErrors::Type error);
 
+  // Convenience method to access the main frame.  Can return NULL, typically
+  // if the page is being closed.
+  WebKit::WebFrame* GetMainFrame();
+
   // The RenderView we are performing translations for.
   RenderView* render_view_;