Convert NOTIMPLs into a bug.

base/process_util_linux.cc

Index: base/process_util_linux.cc
===================================================================
--- base/process_util_linux.cc	(revision 20197)
+++ base/process_util_linux.cc	(working copy)
@@ -261,7 +261,7 @@
 }
 
 size_t ProcessMetrics::GetPeakPagefileUsage() const {
-  NOTIMPLEMENTED();
+  // http://crbug.com/16251
   return 0;
 }
 
@@ -278,17 +278,17 @@
 }
 
 size_t ProcessMetrics::GetPeakWorkingSetSize() const {
-  NOTIMPLEMENTED();
+  // http://crbug.com/16251
   return 0;
 }
 
 size_t ProcessMetrics::GetPrivateBytes() const {
-  NOTIMPLEMENTED();
+  // http://crbug.com/16251
   return 0;
 }
 
 bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
-  NOTIMPLEMENTED();
+  // http://crbug.com/16251
   return false;
 }