permissionrequest API for guest Download.

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 f09ff68e59a6e8288f4b80abfcc5d627bdaf7917..43fd5cde613ffcaeaa2245d53df0f1f074c4a312 100644
--- a/chrome/browser/download/download_request_limiter.cc
+++ b/chrome/browser/download/download_request_limiter.cc
@@ -16,6 +16,7 @@
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
+#include "content/public/browser/render_process_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
 
@@ -208,7 +209,8 @@ void DownloadRequestLimiter::TabDownloadState::NotifyCallbacks(bool allow) {
 
 // DownloadRequestLimiter ------------------------------------------------------
 
-DownloadRequestLimiter::DownloadRequestLimiter() {
+DownloadRequestLimiter::DownloadRequestLimiter()
+    : factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
 }
 
 DownloadRequestLimiter::~DownloadRequestLimiter() {
@@ -273,11 +275,40 @@ void DownloadRequestLimiter::CanDownload(int render_process_host_id,
     return;
   }
 
-  CanDownloadImpl(
-      originating_contents,
+  if (!originating_contents->GetDelegate()) {
+    ScheduleNotification(callback, false);
+    return;
+  }
+
+  base::Callback<void(bool)> can_download_callback = base::Bind(
+      &DownloadRequestLimiter::OnCanDownloadDecided,
+      factory_.GetWeakPtr(),
+      originating_contents, request_id, request_method, callback);

[asanka, 2013/03/27 15:34:53]

|originating_contents| might go away before OnCanDownloadDecided is invoked.
Could you look it up by render_process_host_id, render_view_id?

[lazyboy, 2013/03/27 17:09:22]

Done.

+
+  // 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.

[asanka, 2013/03/27 15:34:53]

Nit: Android also overrides CanDownload to cancel the download and allow the
Download app to handle it. There are overrides for pre-rendering and instant to
suppress downloads from invisible or transient pages. In addition, there's an
override in BrowserPluginGuest that you are working with in this CL. I think
this comment is stale and not all that useful.

[lazyboy, 2013/03/27 17:09:22]

OK, removed.

+  originating_contents->GetDelegate()->CanDownload(
+      originating_contents->GetRenderViewHost(),
       request_id,
       request_method,
-      callback);
+      can_download_callback);
+}
+
+void DownloadRequestLimiter::OnCanDownloadDecided(
+    WebContents* originating_contents,
+    int request_id,
+    const std::string& request_method,
+    const Callback& orig_callback, bool allow) {

[asanka, 2013/03/27 15:34:53]

Can you add a DCHECK here to check whether this callback is getting invoked on
the UI thread?

[lazyboy, 2013/03/27 17:09:22]

Done.

+  if (!allow) {
+    ScheduleNotification(orig_callback, false);
+    return;
+  }
+
+  CanDownloadImpl(originating_contents,
+                  request_id,
+                  request_method,
+                  orig_callback);
 }
 
 void DownloadRequestLimiter::CanDownloadImpl(WebContents* originating_contents,
@@ -286,18 +317,6 @@ void DownloadRequestLimiter::CanDownloadImpl(WebContents* originating_contents,
                                              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.
-  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.
   WebContents* effective_contents = originating_contents;