Speed up the Task Manager on linux.

- Unify the calls to get shared memory and private memory. On Linux, these call the same API and on Linux, it takes >10ms to fetch both values each time it is called.
- Cache the returned memory values. While sorting the task manager by memory, it would make the expensive memory call for each row on each sort operation.

BUG=40033
TEST=Existing task manager tests.

Review URL: http://codereview.chromium.org/2047009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@46938 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 12 insertions, 3 deletions

diff --git a/base/process_util_linux.cc b/base/process_util_linux.cc
index 0a2cc0d..ee44638 100644
--- a/base/process_util_linux.cc
+++ b/base/process_util_linux.cc
@@ -244,10 +244,19 @@ size_t ProcessMetrics::GetPeakWorkingSetSize() const {
   return 0;
 }
 
-size_t ProcessMetrics::GetPrivateBytes() const {
+bool ProcessMetrics::GetMemoryBytes(size_t* private_bytes,
+                                    size_t* shared_bytes) {
   WorkingSetKBytes ws_usage;
-  GetWorkingSetKBytes(&ws_usage);
-  return ws_usage.priv << 10;
+  if (!GetWorkingSetKBytes(&ws_usage))
+    return false;
+
+  if (private_bytes)
+    *private_bytes = ws_usage.priv << 10;
+
+  if (shared_bytes)
+    *shared_bytes = ws_usage.shared * 1024;
+
+  return true;
 }
 
 // Private and Shared working set sizes are obtained from /proc/<pid>/smaps.