diff --git a/base/strings/stringprintf.cc b/base/strings/stringprintf.cc
index f3a57b33e272..537873d71c84 100644
--- a/base/strings/stringprintf.cc
+++ b/base/strings/stringprintf.cc
@@ -6,6 +6,8 @@
 
 #include <errno.h>
 
+#include <vector>
+
 #include "base/scoped_clear_errno.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ -27,7 +29,7 @@ inline int vsnprintfT(char* buffer,
   return base::vsnprintf(buffer, buf_size, format, argptr);
 }
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 inline int vsnprintfT(wchar_t* buffer,
                       size_t buf_size,
                       const wchar_t* format,
@@ -117,7 +119,7 @@ std::string StringPrintf(const char* format, ...) {
   return result;
 }
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 std::wstring StringPrintf(const wchar_t* format, ...) {
   va_list ap;
   va_start(ap, format);
@@ -143,7 +145,7 @@ const std::string& SStringPrintf(std::string* dst, const char* format, ...) {
   return *dst;
 }
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 const std::wstring& SStringPrintf(std::wstring* dst,
                                   const wchar_t* format, ...) {
   va_list ap;
@@ -162,7 +164,7 @@ void StringAppendF(std::string* dst, const char* format, ...) {
   va_end(ap);
 }
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 void StringAppendF(std::wstring* dst, const wchar_t* format, ...) {
   va_list ap;
   va_start(ap, format);
@@ -175,7 +177,7 @@ void StringAppendV(std::string* dst, const char* format, va_list ap) {
   StringAppendVT(dst, format, ap);
 }
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 void StringAppendV(std::wstring* dst, const wchar_t* format, va_list ap) {
   StringAppendVT(dst, format, ap);
 }
diff --git a/base/strings/stringprintf.h b/base/strings/stringprintf.h
index d924a0e59f21..523f7ee55bf3 100644
--- a/base/strings/stringprintf.h
+++ b/base/strings/stringprintf.h
@@ -17,8 +17,7 @@ namespace base {
 // Return a C++ string given printf-like input.
 BASE_EXPORT std::string StringPrintf(const char* format, ...)
     PRINTF_FORMAT(1, 2) WARN_UNUSED_RESULT;
-// OS_ANDROID's libc does not support wchar_t, so several overloads are omitted.
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 BASE_EXPORT std::wstring StringPrintf(const wchar_t* format, ...)
     WPRINTF_FORMAT(1, 2) WARN_UNUSED_RESULT;
 #endif
@@ -31,7 +30,7 @@ BASE_EXPORT std::string StringPrintV(const char* format, va_list ap)
 BASE_EXPORT const std::string& SStringPrintf(std::string* dst,
                                              const char* format, ...)
     PRINTF_FORMAT(2, 3);
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 BASE_EXPORT const std::wstring& SStringPrintf(std::wstring* dst,
                                               const wchar_t* format, ...)
     WPRINTF_FORMAT(2, 3);
@@ -40,9 +39,7 @@ BASE_EXPORT const std::wstring& SStringPrintf(std::wstring* dst,
 // Append result to a supplied string.
 BASE_EXPORT void StringAppendF(std::string* dst, const char* format, ...)
     PRINTF_FORMAT(2, 3);
-#if !defined(OS_ANDROID)
-// TODO(evanm): this is only used in a few places in the code;
-// replace with string16 version.
+#if defined(OS_WIN)
 BASE_EXPORT void StringAppendF(std::wstring* dst, const wchar_t* format, ...)
     WPRINTF_FORMAT(2, 3);
 #endif
@@ -51,7 +48,7 @@ BASE_EXPORT void StringAppendF(std::wstring* dst, const wchar_t* format, ...)
 // string.  All other routines are just convenience wrappers around it.
 BASE_EXPORT void StringAppendV(std::string* dst, const char* format, va_list ap)
     PRINTF_FORMAT(2, 0);
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
 BASE_EXPORT void StringAppendV(std::wstring* dst,
                                const wchar_t* format, va_list ap)
     WPRINTF_FORMAT(2, 0);
diff --git a/base/strings/stringprintf_unittest.cc b/base/strings/stringprintf_unittest.cc
index 4935b553b0e4..321747869a07 100644
--- a/base/strings/stringprintf_unittest.cc
+++ b/base/strings/stringprintf_unittest.cc
@@ -31,7 +31,7 @@ TEST(StringPrintfTest, StringPrintfEmpty) {
 
 TEST(StringPrintfTest, StringPrintfMisc) {
   EXPECT_EQ("123hello w", StringPrintf("%3d%2s %1c", 123, "hello", 'w'));
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
   EXPECT_EQ(L"123hello w", StringPrintf(L"%3d%2ls %1lc", 123, L"hello", 'w'));
 #endif
 }
@@ -41,7 +41,7 @@ TEST(StringPrintfTest, StringAppendfEmptyString) {
   StringAppendF(&value, "%s", "");
   EXPECT_EQ("Hello", value);
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
   std::wstring valuew(L"Hello");
   StringAppendF(&valuew, L"%ls", L"");
   EXPECT_EQ(L"Hello", valuew);
@@ -53,7 +53,7 @@ TEST(StringPrintfTest, StringAppendfString) {
   StringAppendF(&value, " %s", "World");
   EXPECT_EQ("Hello World", value);
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
   std::wstring valuew(L"Hello");
   StringAppendF(&valuew, L" %ls", L"World");
   EXPECT_EQ(L"Hello World", valuew);
@@ -65,7 +65,7 @@ TEST(StringPrintfTest, StringAppendfInt) {
   StringAppendF(&value, " %d", 123);
   EXPECT_EQ("Hello 123", value);
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
   std::wstring valuew(L"Hello");
   StringAppendF(&valuew, L" %d", 123);
   EXPECT_EQ(L"Hello 123", valuew);
@@ -90,7 +90,7 @@ TEST(StringPrintfTest, StringPrintfBounds) {
     SStringPrintf(&out, "%s", src);
     EXPECT_STREQ(src, out.c_str());
 
-#if !defined(OS_ANDROID)
+#if defined(OS_WIN)
     srcw[kSrcLen - i] = 0;
     std::wstring outw;
     SStringPrintf(&outw, L"%ls", srcw);