Code: void ChromeDownloadDelegate::RequestHTTPGetDownload(
    const std::string& url,
    const std::string& user_agent,
    const std::string& content_disposition,
    const std::string& mime_type,
    const std::string& cookie,
    const std::string& referer,
    const base::string16& file_name,
    int64_t content_length,
    bool has_user_gesture,
    bool must_download) {
  JNIEnv* env = base::android::AttachCurrentThread();
  ScopedJavaLocalRef<jstring> jurl =
      ConvertUTF8ToJavaString(env, url);
  ScopedJavaLocalRef<jstring> juser_agent =
      ConvertUTF8ToJavaString(env, user_agent);
  ScopedJavaLocalRef<jstring> jcontent_disposition =
      ConvertUTF8ToJavaString(env, content_disposition);
  ScopedJavaLocalRef<jstring> jmime_type =
      ConvertUTF8ToJavaString(env, mime_type);
  ScopedJavaLocalRef<jstring> jcookie =
      ConvertUTF8ToJavaString(env, cookie);
  ScopedJavaLocalRef<jstring> jreferer =
      ConvertUTF8ToJavaString(env, referer);
  ScopedJavaLocalRef<jstring> jfilename =
      base::android::ConvertUTF16ToJavaString(env, file_name);
  Java_ChromeDownloadDelegate_requestHttpGetDownload(
      env, java_ref_, jurl, juser_agent, jcontent_disposition, jmime_type,
      jcookie, jreferer, has_user_gesture, jfilename, content_length,
      must_download);
}

Vulnerability Type: 
CWE ID: CWE-254
Summary: The UnescapeURLWithAdjustmentsImpl implementation in net/base/escape.cc in Google Chrome before 45.0.2454.85 does not prevent display of Unicode LOCK characters in the omnibox, which makes it easier for remote attackers to spoof the SSL lock icon by placing one of these characters at the end of a URL, as demonstrated by the omnibox in localizations for right-to-left languages.
Commit Message: Clean up Android DownloadManager code as most download now go through Chrome Network stack

The only exception is OMA DRM download.
And it only applies to context menu download interception.
Clean up the remaining unused code now.

BUG=647755

Review-Url: https://codereview.chromium.org/2371773003
Cr-Commit-Position: refs/heads/master@{#421332}