move file access permission logic to DownloadResourceThrottle

chrome/browser/download/download_resource_throttle.cc

Index: chrome/browser/download/download_resource_throttle.cc
diff --git a/chrome/browser/download/download_resource_throttle.cc b/chrome/browser/download/download_resource_throttle.cc
index a8e2afa02b153b8f36aa26d8c0ec260aabac9a95..2d0b9e088a68892a028fb224c3aa68dbaea2533e 100644
--- a/chrome/browser/download/download_resource_throttle.cc
+++ b/chrome/browser/download/download_resource_throttle.cc
@@ -6,10 +6,80 @@
 
 #include "base/bind.h"
 #include "chrome/browser/download/download_stats.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_controller.h"
 
+#if defined(OS_ANDROID)
+#include "content/public/browser/android/download_controller_android.h"
+#include "content/public/browser/render_view_host.h"
+
+using content::DownloadControllerAndroid;
+#endif
+
+using content::BrowserThread;
+
+namespace {
+
+void OnCanDownloadDecided(base::WeakPtr<DownloadResourceThrottle> throttle,
+                          bool allow) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&DownloadResourceThrottle::ContinueDownload, throttle, allow));
+}
+
+void CanDownload(
+    scoped_ptr<DownloadResourceThrottle::DownloadRequestInfo> info) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  info->limiter->CanDownload(info->render_process_id, info->render_view_id,
+                             info->url, info->request_method,
+                             info->continue_callback);
+}
+
+#if defined(OS_ANDROID)
+void OnAcquireFileAccessPermissionDone(
+    scoped_ptr<DownloadResourceThrottle::DownloadRequestInfo> info,
+    bool granted) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  if (granted)
+    CanDownload(info.Pass());
+  else
+    info->continue_callback.Run(false);
+}
+#endif
+
+void CanDownloadOnUIThread(
+    scoped_ptr<DownloadResourceThrottle::DownloadRequestInfo> info) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+#if defined(OS_ANDROID)
+  content::DownloadControllerAndroid::Get()->AcquireFileAccessPermission(
+      info->render_process_id, info->render_view_id,
+      base::Bind(&OnAcquireFileAccessPermissionDone,
+                 base::Passed(info.Pass())));
+#else
+  CanDownload(info.Pass());
+#endif
+}
+
+}  // namespace
+
+DownloadResourceThrottle::DownloadRequestInfo::DownloadRequestInfo(
+    scoped_refptr<DownloadRequestLimiter> limiter,
+    int render_process_id,
+    int render_view_id,
+    const GURL& url,
+    const std::string& request_method,
+    const DownloadRequestLimiter::Callback& continue_callback)
+    : limiter(limiter),
+      render_process_id(render_process_id),
+      render_view_id(render_view_id),
+      url(url),
+      request_method(request_method),
+      continue_callback(continue_callback) {}
+
+DownloadResourceThrottle::DownloadRequestInfo::~DownloadRequestInfo() {}
+
 DownloadResourceThrottle::DownloadResourceThrottle(
-    DownloadRequestLimiter* limiter,
+    scoped_refptr<DownloadRequestLimiter> limiter,
     int render_process_id,
     int render_view_id,
     const GURL& url,
@@ -17,13 +87,14 @@ DownloadResourceThrottle::DownloadResourceThrottle(
     : querying_limiter_(true),
       request_allowed_(false),
       request_deferred_(false) {
-  limiter->CanDownloadOnIOThread(
-      render_process_id,
-      render_view_id,
-      url,
-      request_method,
-      base::Bind(&DownloadResourceThrottle::ContinueDownload,
-                 AsWeakPtr()));
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(
+          &CanDownloadOnUIThread,
+          base::Passed(scoped_ptr<DownloadRequestInfo>(new DownloadRequestInfo(
+              limiter, render_process_id, render_view_id, url, request_method,
+              base::Bind(&OnCanDownloadDecided, AsWeakPtr()))))));
 }
 
 DownloadResourceThrottle::~DownloadResourceThrottle() {
@@ -62,6 +133,7 @@ void DownloadResourceThrottle::WillDownload(bool* defer) {
 }
 
 void DownloadResourceThrottle::ContinueDownload(bool allow) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   querying_limiter_ = false;
   request_allowed_ = allow;