Changing OOM range to 0, 1000 and tweaking OOM algorithm.

base/process_util.h

Index: base/process_util.h
diff --git a/base/process_util.h b/base/process_util.h
index b98e266a97870d7231279b6cc91c9194dfa60638..1a70f932b9c416e072bc70ea134f9e7db3c5deb3 100644
--- a/base/process_util.h
+++ b/base/process_util.h
@@ -175,9 +175,13 @@ BASE_EXPORT int ParseProcStatCPU(const std::string& input);
 
 static const char kAdjustOOMScoreSwitch[] = "--adjust-oom-score";
 
-// This adjusts /proc/process/oom_adj so the Linux OOM killer will prefer
-// certain process types over others. The range for the adjustment is
-// [-17,15], with [0,15] being user accessible.
+// This adjusts /proc/<pid>/oom_score_adj so the Linux OOM killer will
+// prefer to kill certain process types over others. The range for the
+// adjustment is [-1000, 1000], with [0, 1000] being user accessible.
+// If the Linux system doesn't support the newer oom_score_adj range
+// of [0, 1000], then we revert to using the older oom_adj, and
+// translate the given value into [0, 15].  Some aliasing of values
+// may occur in that case, of course.
 BASE_EXPORT bool AdjustOOMScore(ProcessId process, int score);
 #endif