ui/base/dragdrop: Remove dead SetDownloadFileInfo code.

OSExchangeData::SetDownloadFileInfo is no longer used anywhere, so
remove it. The function it calls,
OSExchangeDataProvider::SetDownloadFileInfo[1], is still used.

Refactoring change only, so no functional changes expected.

[1]: https://source.chromium.org/chromium/chromium/src/+/master:ui/base/dragdrop/os_exchange_data_provider.h;l=93;drc=c741e070dbfcc33b2369e7a5131be87c7b21bb99

Change-Id: I623c86eca682450a8c02d3d46dda0b80e4852252
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404538
Commit-Queue: Darwin Huang <huangdarwin@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Auto-Submit: Darwin Huang <huangdarwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806418}

ui/base/dragdrop/os_exchange_data.cc

@@ -144,10 +144,6 @@ bool OSExchangeData::GetVirtualFilesAsTempFiles(
         callback) const {
   return provider_->GetVirtualFilesAsTempFiles(std::move(callback));
 }
-
-void OSExchangeData::SetDownloadFileInfo(DownloadFileInfo* download) {
-  provider_->SetDownloadFileInfo(download);
-}
 #endif
 
 #if defined(USE_AURA)

ui/base/dragdrop/os_exchange_data.h

@@ -176,9 +176,6 @@ class COMPONENT_EXPORT(UI_BASE) OSExchangeData {
                                   base::FilePath,
                                   /*display name*/ base::FilePath>>&)> callback)
       const;
-
-  // Adds a download file with full path (CF_HDROP).
-  void SetDownloadFileInfo(DownloadFileInfo* download);
 #endif
 
 #if defined(USE_AURA)

ui/views/controls/textfield/textfield_unittest.cc

@@ -1977,7 +1977,7 @@ TEST_F(TextfieldTest, DragAndDrop_AcceptDrop) {
   bad_data.SetFileContents(base::FilePath(L"x"), "x");
   bad_data.SetHtml(base::string16(ASCIIToUTF16("x")), GURL("x.org"));
   ui::DownloadFileInfo download(base::FilePath(), nullptr);
-  bad_data.SetDownloadFileInfo(&download);
+  bad_data.provider().SetDownloadFileInfo(&download);
   EXPECT_FALSE(textfield_->CanDrop(bad_data));
 }
 #endif