Make UTF8ToWide take a StringPiece, to avoid copying to a std::string.

The previous prototype took only a std::string, unless you used the less convenient output parameter version.  This required copying char* input to a std::string.  Using a StringPiece the input will be implicitly both std::string and char* without any copying.  This helps especially on Linux, where all input we get will be in utf8 char*.

Review URL: http://codereview.chromium.org/40106


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@10985 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 3 insertions, 2 deletions

diff --git a/base/string_util.h b/base/string_util.h
index a688828..7f86009 100644
--- a/base/string_util.h
+++ b/base/string_util.h
@@ -14,6 +14,7 @@
 
 #include "base/basictypes.h"
 #include "base/string16.h"
+#include "base/string_piece.h"  // For implicit conversions.
 
 // Safe standard library wrappers for all platforms.
 
@@ -186,7 +187,7 @@ string16 ASCIIToUTF16(const std::string& ascii);
 bool WideToUTF8(const wchar_t* src, size_t src_len, std::string* output);
 std::string WideToUTF8(const std::wstring& wide);
 bool UTF8ToWide(const char* src, size_t src_len, std::wstring* output);
-std::wstring UTF8ToWide(const std::string& utf8);
+std::wstring UTF8ToWide(const StringPiece& utf8);
 
 bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output);
 string16 WideToUTF16(const std::wstring& wide);
diff --git a/base/string_util_icu.cc b/base/string_util_icu.cc
index eae66d1..4debcca 100644
--- a/base/string_util_icu.cc
+++ b/base/string_util_icu.cc
@@ -198,7 +198,7 @@ bool WideToUTF8(const wchar_t* src, size_t src_len, std::string* output) {
   return ConvertUnicode<wchar_t, std::string>(src, src_len, output);
 }
 
-std::wstring UTF8ToWide(const std::string& utf8) {
+std::wstring UTF8ToWide(const StringPiece& utf8) {
   std::wstring ret;
   if (utf8.empty())
     return ret;