Exclude files from FileSelectChooser if they can't convert to WebStrings.

chrome/browser/file_select_helper.cc

Index: chrome/browser/file_select_helper.cc
diff --git a/chrome/browser/file_select_helper.cc b/chrome/browser/file_select_helper.cc
index 91aa51e1411d34e09b7c3cecd23a8174cc2f082d..1f106cf5e7f7d32fdb2ed37347f0d9c19fe78939 100644
--- a/chrome/browser/file_select_helper.cc
+++ b/chrome/browser/file_select_helper.cc
@@ -320,6 +320,11 @@ void FileSelectHelper::NotifyRenderFrameHostAndEnd(
 
   std::vector<content::FileChooserFileInfo> chooser_files;
   for (const auto& file : files) {
+    // Exclude files whose paths can't be converted into WebStrings, since Blink
+    // won't be able to handle those.
+    if (file.local_path.AsUTF8Unsafe().empty())

[asanka, 2017/04/13 17:21:22]

Shall we move this logic to a static function and call it from
NotifyRenderFrameHostAndEndAfterConversion()?

This way:
* That function can be unit tested separately.
* Filtering logic will be applied to ChromeOS's file chooser results as well.
Technically those filenames should always be valid UTF-8. But we should apply
filtering consistently.

For an end-to-end test, we could rely on something like what we did in
ppapi_filechooser_browsertest.cc where we switch out the SelectFileDialogFactory
and replace it with something that'll act like the user selected some hardcoded
filename.

It'll be trivial to add  a test to ppapi_filechooser_browsertest to test the
logic being added here, but that'd violate the principle of least surprise for
what's tested where :-)

There *has* to be an end-to-end test where we exercise FileSelectHelper based on
a renderer initiated "open" request other than PPAPI. But I couldn't find one.

[Charlie Reis, 2017/04/14 19:28:15]

Thanks for the suggestion!  If we're going to be filtering the vector of files
after we build it, though, I might as well do it in RenderFrameHostImpl.  That
covers even more cases (including content_browsertests that mock out
FileSelectHelper), and it keeps both the fix and test closer to the code that
does the renderer kill.

I've updated the CL to do that-- can you take another look?

+      continue;
+
     content::FileChooserFileInfo chooser_file;
     chooser_file.file_path = file.local_path;
     chooser_file.display_name = file.display_name;