Make CPU profiler do not hog 100% of CPU.

src/base/platform/platform-posix.cc

Index: src/base/platform/platform-posix.cc
diff --git a/src/base/platform/platform-posix.cc b/src/base/platform/platform-posix.cc
index 78b8d782580e4a2897aa0da8e7196bef7aed4f4b..8a037c02d335eeb8a961072b5749825a6040568c 100644
--- a/src/base/platform/platform-posix.cc
+++ b/src/base/platform/platform-posix.cc
@@ -219,9 +219,8 @@ size_t OS::AllocateAlignment() {
 }
 
 
-void OS::Sleep(int milliseconds) {
-  useconds_t ms = static_cast<useconds_t>(milliseconds);
-  usleep(1000 * ms);
+void OS::Sleep(TimeDelta interval) {
+  usleep(static_cast<useconds_t>(interval.InMicroseconds()));
 }