Fix some grammatical errors in base/

base/process_util_linux.cc

Index: base/process_util_linux.cc
diff --git a/base/process_util_linux.cc b/base/process_util_linux.cc
index be86bc7cf19a8a2dd14a3ffb18e3f8d875d95641..91867d54c3dd41e815086dcb51d496fc55f6fcfe 100644
--- a/base/process_util_linux.cc
+++ b/base/process_util_linux.cc
@@ -756,7 +756,7 @@ void EnableTerminationOnOutOfMemory() {
 
 // NOTE: This is not the only version of this function in the source:
 // the setuid sandbox (in process_util_linux.c, in the sandbox source)
-// also has it's own C version.
+// also has its own C version.
 bool AdjustOOMScore(ProcessId process, int score) {
   if (score < 0 || score > kMaxOomScore)
     return false;