Mac: make save/open dialogs operate as tab-modal sheets....

chrome/browser/download/download_request_manager.cc

Index: chrome/browser/download/download_request_manager.cc
diff --git a/chrome/browser/download/download_request_manager.cc b/chrome/browser/download/download_request_manager.cc
index 83811e2693ad079c2f94ebc9af7ce9b7fc86b61e..50d4e3c7daea14e3581c466603f578cdaa494f98 100644
--- a/chrome/browser/download/download_request_manager.cc
+++ b/chrome/browser/download/download_request_manager.cc
@@ -58,19 +58,22 @@ void DownloadRequestManager::TabDownloadState::OnUserGesture() {
   }
 }
 
-void DownloadRequestManager::TabDownloadState::PromptUserForDownload(
+bool DownloadRequestManager::TabDownloadState::PromptUserForDownload(
     TabContents* tab,
     DownloadRequestManager::Callback* callback) {
   callbacks_.push_back(callback);
 
   if (is_showing_prompt())
-    return;  // Already showing prompt.
+    return true;  // Already showing prompt.
 
   if (DownloadRequestManager::delegate_) {
     NotifyCallbacks(DownloadRequestManager::delegate_->ShouldAllowDownload());
   } else {
     dialog_delegate_ = DownloadRequestDialogDelegate::Create(tab, this);
+    if (!dialog_delegate_)
+      return false;
   }
+  return true;
 }
 
 void DownloadRequestManager::TabDownloadState::Cancel() {
@@ -261,7 +264,11 @@ void DownloadRequestManager::CanDownloadImpl(
       break;
 
     case PROMPT_BEFORE_DOWNLOAD:
-      state->PromptUserForDownload(effective_tab, callback);
+      // Conceivably, for some reason (e.g., already have another tab-modal
+      // dialog up), we may not be able display a prompt. In that case, default
+      // to denial.
+      if (!state->PromptUserForDownload(effective_tab, callback))
+        ScheduleNotification(callback, false);
       break;
 
     default: