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, 6 insertions, 4 deletions

diff --git a/base/process_util.h b/base/process_util.h
index ec3510a..b8bcfd4 100644
--- a/base/process_util.h
+++ b/base/process_util.h
@@ -481,10 +481,12 @@ class ProcessMetrics {
   size_t GetWorkingSetSize() const;
   // Returns the peak working set size, in bytes.
   size_t GetPeakWorkingSetSize() const;
-  // Returns private usage, in bytes. Private bytes is the amount
-  // of memory currently allocated to a process that cannot be shared.
-  // Note: returns 0 on unsupported OSes: prior to XP SP2.
-  size_t GetPrivateBytes() const;
+  // Returns private and sharedusage, in bytes. Private bytes is the amount of
+  // memory currently allocated to a process that cannot be shared. Returns
+  // false on platform specific error conditions.  Note: |private_bytes|
+  // returns 0 on unsupported OSes: prior to XP SP2.
+  bool GetMemoryBytes(size_t* private_bytes,
+                      size_t* shared_bytes);
   // Fills a CommittedKBytes with both resident and paged
   // memory usage as per definition of CommittedBytes.
   void GetCommittedKBytes(CommittedKBytes* usage) const;