reintroduce InterceptDownloadResourceThrottle for some OMA DRM downloads

chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc

Index: chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
diff --git a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
index 154f28f0fc415a463a836944ad95249484fa5bc8..00cea354c24bdbb43025621d163108bd31603b5f 100644
--- a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
+++ b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
@@ -106,6 +106,7 @@
 #endif
 
 #if defined(OS_ANDROID)
+#include "chrome/browser/android/download/intercept_download_resource_throttle.h"
 #include "chrome/browser/android/offline_pages/downloads/resource_throttle.h"
 #include "chrome/browser/loader/data_reduction_proxy_resource_throttle_android.h"
 #include "components/navigation_interception/intercept_navigation_delegate.h"
@@ -542,6 +543,11 @@ void ChromeResourceDispatcherHostDelegate::DownloadStarting(
     throttles->push_back(base::MakeUnique<DownloadResourceThrottle>(
         download_request_limiter_, info->GetWebContentsGetterForRequest(),
         request->url(), request->method()));
+#if defined(OS_ANDROID)
+    throttles->push_back(
+        base::MakeUnique<InterceptDownloadResourceThrottle>(
+            request, info->GetWebContentsGetterForRequest()));
+#endif

[asanka, 2017/01/19 23:59:13]

This is the wrong place to add this resource throttle since it bypasses the
SafeBrowsing checks for explicit downloads. It should be added after
AppendStandardResourceThrottles() below.

Note that is_new_request and is_content_initiated are both true for <a download>
type downloads.

[qinmin, 2017/01/20 00:06:10]

Done.

   }
 
   // If this isn't a new request, the standard resource throttles have already