Mac: stop zombie ps processes from being created.

This fixes two bugs:
- the output buffer for the ps command being run could be too small (fix: buffer
  enlargened); and
- if the output buffer was too small, waitpid() wouldn't be called (fix: always
  call waitpid(), obviously).

BUG=31378
TEST=On a big, long-running Chrome/Chromium (with many processes, e.g., renderers), check that there are no zombie ps processes (with PPID the browser process); looking at about:memory may help speed up the creation of such zombies. Also, run the new test, ProcessUtilTest.GetAppOutputRestrictedNoZombies.

Review URL: http://codereview.chromium.org/523033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35456 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 6 insertions, 1 deletions

diff --git a/chrome/browser/process_info_snapshot.h b/chrome/browser/process_info_snapshot.h
index 88064c6..14e8ceb 100644
--- a/chrome/browser/process_info_snapshot.h
+++ b/chrome/browser/process_info_snapshot.h
@@ -31,9 +31,14 @@ class ProcessInfoSnapshot {
   ProcessInfoSnapshot();
   ~ProcessInfoSnapshot();
 
+  // Maximum size of lists of PIDs which this class will accept; used in
+  // |Sample()| below.
+  static const size_t kMaxPidListSize;
+
   // Capture a snapshot of process memory information (by running ps) for the
   // given list of PIDs. Call only from the file thread.
-  //   |pid_list| - list of |ProcessId|s on which to capture information.
+  //   |pid_list| - list of |ProcessId|s on which to capture information; must
+  //     have no more than |kMaxPidListSize| (above) entries,
   //   returns - |true| if okay, |false| on error.
   bool Sample(std::vector<base::ProcessId> pid_list);