Update from https://crrev.com/307330

base/process/process_metrics_posix.cc

Index: base/process/process_metrics_posix.cc
diff --git a/base/process/process_metrics_posix.cc b/base/process/process_metrics_posix.cc
index ea79d7348ff47f58fa16f946577386052d692429..7afae214d4a8708db1f6d5df59a28c7a301ea47d 100644
--- a/base/process/process_metrics_posix.cc
+++ b/base/process/process_metrics_posix.cc
@@ -12,9 +12,8 @@
 namespace base {
 
 int64 TimeValToMicroseconds(const struct timeval& tv) {
-  static const int kMicrosecondsPerSecond = 1000000;
   int64 ret = tv.tv_sec;  // Avoid (int * int) integer overflow.
-  ret *= kMicrosecondsPerSecond;
+  ret *= Time::kMicrosecondsPerSecond;
   ret += tv.tv_usec;
   return ret;
 }