Enable url check in download_manager, with a simple UI (it may need polish). The whole thing is still behind a flag.
The download_file_manager will start a url check with safebrowsing. It goes parallel with file creation operation. When url is checked to be dangerous, the UI dialog will show  the dialog. 
TEST=download_manager_unittest
BUG=60822

Review URL: http://codereview.chromium.org/6410050

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@76123 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index a9d0897..fdaaf89c 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -850,6 +850,8 @@
         'browser/download/download_request_infobar_delegate.h',
         'browser/download/download_request_limiter.cc',
         'browser/download/download_request_limiter.h',
+        'browser/download/download_safe_browsing_client.cc',
+        'browser/download/download_safe_browsing_client.h',
         'browser/download/download_shelf.cc',
         'browser/download/download_shelf.h',
         'browser/download/download_started_animation.h',