base: Make TimeDurationFormat* report failures.

base/i18n/time_formatting.h

Index: base/i18n/time_formatting.h
diff --git a/base/i18n/time_formatting.h b/base/i18n/time_formatting.h
index ba09b44f3a60613215afa60a5114c29d3f13b30c..41793b339ceb02879f49f7235433b8db7a09f964 100644
--- a/base/i18n/time_formatting.h
+++ b/base/i18n/time_formatting.h
@@ -8,6 +8,7 @@
 #ifndef BASE_I18N_TIME_FORMATTING_H_
 #define BASE_I18N_TIME_FORMATTING_H_
 
+#include "base/compiler_specific.h"
 #include "base/i18n/base_i18n_export.h"
 #include "base/strings/string16.h"
 
@@ -46,6 +47,10 @@ enum DateFormat {
   DATE_FORMAT_MONTH_WEEKDAY_DAY,
 };
 
+// TODO(derat@chromium.org): Update all of these functions to return boolean
+// "success" values and use out-params for formatted strings:
+// http://crbug.com/698802
+
 // Returns the time of day, e.g., "3:07 PM".
 BASE_I18N_EXPORT string16 TimeFormatTimeOfDay(const Time& time);
 
@@ -95,28 +100,31 @@ BASE_I18N_EXPORT string16 TimeFormatWithPattern(const Time& time,
                                                 const char* pattern);
 
 // Formats a time duration of hours and minutes into various formats, e.g.,
-// "3:07" or "3 hours, 7 minutes".  See DurationFormatWidth for details.
+// "3:07" or "3 hours, 7 minutes", and returns true on success. See
+// DurationFormatWidth for details.
 //
 // Please don't use width = DURATION_WIDTH_NUMERIC when the time duration
 // can possibly be larger than 24h, as the hour value will be cut below 24
 // after formatting.
 // TODO(chengx): fix function output when width = DURATION_WIDTH_NUMERIC
 // (http://crbug.com/675791)
-BASE_I18N_EXPORT string16 TimeDurationFormat(const TimeDelta time,
-                                             const DurationFormatWidth width);
+BASE_I18N_EXPORT bool TimeDurationFormat(const TimeDelta time,
+                                         const DurationFormatWidth width,
+                                         string16* out) WARN_UNUSED_RESULT;
 
 // Formats a time duration of hours, minutes and seconds into various formats,
-// e.g., "3:07:30" or "3 hours, 7 minutes, 30 seconds". See DurationFormatWidth
-// for details.
+// e.g., "3:07:30" or "3 hours, 7 minutes, 30 seconds", and returns true on
+// success. See DurationFormatWidth for details.
 //
 // Please don't use width = DURATION_WIDTH_NUMERIC when the time duration
 // can possibly be larger than 24h, as the hour value will be cut below 24
 // after formatting.
 // TODO(chengx): fix function output when width = DURATION_WIDTH_NUMERIC
 // (http://crbug.com/675791)
-BASE_I18N_EXPORT string16
-TimeDurationFormatWithSeconds(const TimeDelta time,
-                              const DurationFormatWidth width);
+BASE_I18N_EXPORT bool TimeDurationFormatWithSeconds(
+    const TimeDelta time,
+    const DurationFormatWidth width,
+    string16* out) WARN_UNUSED_RESULT;
 
 // Formats a date interval into various formats, e.g. "2 December - 4 December"
 // or "March 2016 - December 2016". See DateFormat for details.