Don't prompt for download location on Android

chrome/browser/download/download_prefs.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/download/download_prefs.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
@@ skipping 138 matching lines @@
   if (!prefs->GetBoolean(prefs::kDownloadDirUpgraded)) {
     base::FilePath current_download_dir = prefs->GetFilePath(
         prefs::kDownloadDefaultDirectory);
     if (DownloadPathIsDangerous(current_download_dir)) {
       prefs->SetFilePath(prefs::kDownloadDefaultDirectory,
                          GetDefaultDownloadDirectoryForProfile());
     }
     prefs->SetBoolean(prefs::kDownloadDirUpgraded, true);
   }
 
+// Ignore "Always prompt for download location" preference on Android.
+#if defined(OS_ANDROID)
+  prompt_for_download_.SetValue(false);

[asanka, 2016/10/07 16:10:18]

I don't think we can set the pref without initializing it. And once we do, we
are stuck with the original problem. Doesn't this cause a DCHECK?

[qinmin, 2016/10/07 16:25:14]

Good catch. Switched to always return false in
DownloadTargetDeterminer::ShouldPromptForDownload()

+#else
   prompt_for_download_.Init(prefs::kPromptForDownload, prefs);
+#endif
   download_path_.Init(prefs::kDownloadDefaultDirectory, prefs);
   save_file_path_.Init(prefs::kSaveFileDefaultDirectory, prefs);
   save_file_type_.Init(prefs::kSaveFileType, prefs);
 
   // We store any file extension that should be opened automatically at
   // download completion in this pref.
   std::string extensions_to_open =
       prefs->GetString(prefs::kDownloadExtensionsToOpen);
 
   for (const auto& extension_string : base::SplitString(
@@ skipping 218 matching lines @@
     extensions.erase(extensions.size() - 1);
 
   profile_->GetPrefs()->SetString(prefs::kDownloadExtensionsToOpen, extensions);
 }
 
 bool DownloadPrefs::AutoOpenCompareFunctor::operator()(
     const base::FilePath::StringType& a,
     const base::FilePath::StringType& b) const {
   return base::FilePath::CompareLessIgnoreCase(a, b);
 }