FTP: improve character encoding detection in cases where ICU's first guess is wrong.

base/i18n/icu_encoding_detection.h

Index: base/i18n/icu_encoding_detection.h
diff --git a/base/i18n/icu_encoding_detection.h b/base/i18n/icu_encoding_detection.h
index e7e62536ac332e60744341524e939804bbc94dc6..cdc4cb7ba31026a7292400fb460d699b522c974d 100644
--- a/base/i18n/icu_encoding_detection.h
+++ b/base/i18n/icu_encoding_detection.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <string>
+#include <vector>
 
 namespace base {
 
@@ -15,6 +16,11 @@ namespace base {
 // Returns true on success.
 bool DetectEncoding(const std::string& text, std::string* encoding);
 
+// Detect all possible encodings of |text| and put their names
+// (as returned by ICU) in |encodings|. Returns true on success.
+bool DetectAllEncodings(const std::string& text,
+                        std::vector<std::string>* encodings);
+
 }  // namespace base
 
 #endif  // BASE_I18N_ICU_ENCODING_DETECTION_H_