Fix crash when download from popup.

chrome/browser/download/download_request_limiter.cc

Index: chrome/browser/download/download_request_limiter.cc
diff --git a/chrome/browser/download/download_request_limiter.cc b/chrome/browser/download/download_request_limiter.cc
index 91bb6cbc37578e3c8febf9371fe8b400e8b9988a..3fe73ba5c0685110dc512e9c83a7fe6f4f562b95 100644
--- a/chrome/browser/download/download_request_limiter.cc
+++ b/chrome/browser/download/download_request_limiter.cc
@@ -211,7 +211,8 @@ DownloadRequestLimiter::~DownloadRequestLimiter() {
 
 DownloadRequestLimiter::DownloadStatus
     DownloadRequestLimiter::GetDownloadStatus(WebContents* tab) {
-  TabDownloadState* state = GetDownloadState(&tab->GetController(), NULL, false);
+  TabDownloadState* state =
+      GetDownloadState(&tab->GetController(), NULL, false);
   return state ? state->download_status() : ALLOW_ONE_DOWNLOAD;
 }
 
@@ -270,49 +271,55 @@ void DownloadRequestLimiter::CanDownload(int render_process_host_id,
                                          const Callback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  WebContents* originating_tab =
+  WebContents* originating_contents =
       tab_util::GetWebContentsByID(render_process_host_id, render_view_id);
-  if (!originating_tab) {
+  if (!originating_contents) {
     // The tab was closed, don't allow the download.
     ScheduleNotification(callback, false);
     return;
   }
 
   CanDownloadImpl(
-      TabContentsWrapper::GetCurrentWrapperForContents(originating_tab),
+      originating_contents,
       request_id,
       request_method,
       callback);
 }
 
-void DownloadRequestLimiter::CanDownloadImpl(
-    TabContentsWrapper* originating_tab,
-    int request_id,
-    const std::string& request_method,
-    const Callback& callback) {
-  DCHECK(originating_tab);
+void DownloadRequestLimiter::CanDownloadImpl(WebContents* originating_contents,
+                                             int request_id,
+                                             const std::string& request_method,
+                                             const Callback& callback) {
+  DCHECK(originating_contents);
 
   // FYI: Chrome Frame overrides CanDownload in ExternalTabContainer in order
   // to cancel the download operation in chrome and let the host browser
   // take care of it.
-  WebContents* tab = originating_tab->web_contents();
-  if (tab->GetDelegate() && !tab->GetDelegate()->CanDownload(
-      tab->GetRenderViewHost(), request_id, request_method)) {
+  if (originating_contents->GetDelegate() &&
+      !originating_contents->GetDelegate()->CanDownload(
+          originating_contents->GetRenderViewHost(),
+          request_id,
+          request_method)) {
     ScheduleNotification(callback, false);
     return;
   }
 
   // If the tab requesting the download is a constrained popup that is not
   // shown, treat the request as if it came from the parent.
-  TabContentsWrapper* effective_wrapper = originating_tab;
-  if (effective_wrapper->blocked_content_tab_helper()->delegate()) {
-    effective_wrapper = effective_wrapper->blocked_content_tab_helper()->
-        delegate()->GetConstrainingContentsWrapper(effective_wrapper);
+  WebContents* effective_contents = originating_contents;
+  TabContentsWrapper* originating_wrapper =
+      TabContentsWrapper::GetCurrentWrapperForContents(originating_contents);
+  if (originating_wrapper &&
+      originating_wrapper->blocked_content_tab_helper()->delegate()) {
+    effective_contents = originating_wrapper->blocked_content_tab_helper()->
+        delegate()->GetConstrainingContentsWrapper(originating_wrapper)->
+            web_contents();
   }
 
   TabDownloadState* state = GetDownloadState(
-      &effective_wrapper->web_contents()->GetController(),
-      &tab->GetController(), true);
+      &effective_contents->GetController(),
+      &originating_contents->GetController(),
+      true);
   switch (state->download_status()) {
     case ALLOW_ALL_DOWNLOADS:
       if (state->download_count() && !(state->download_count() %
@@ -332,7 +339,7 @@ void DownloadRequestLimiter::CanDownloadImpl(
       break;
 
     case PROMPT_BEFORE_DOWNLOAD:
-      state->PromptUserForDownload(effective_wrapper->web_contents(), callback);
+      state->PromptUserForDownload(effective_contents, callback);
       state->increment_download_count();
       break;