[tools/perf] Refactor octane benchmark to use GetSystemTotalPhysicalMemory

tools/perf/benchmarks/octane.py

Index: tools/perf/benchmarks/octane.py
diff --git a/tools/perf/benchmarks/octane.py b/tools/perf/benchmarks/octane.py
index 4c7aa5ee947178ce06061895f18e007dfdd42143..02fb9bf46eff08a0642e55e8c588ddd53aa7226e 100644
--- a/tools/perf/benchmarks/octane.py
+++ b/tools/perf/benchmarks/octane.py
@@ -80,9 +80,8 @@ class _OctaneMeasurement(legacy_page_test.LegacyPageTest):
     self._power_metric = power.PowerMetric(platform)
 
   def WillNavigateToPage(self, page, tab):
-    memory_stats = tab.browser.memory_stats
-    if ('SystemTotalPhysicalMemory' in memory_stats and
-        memory_stats['SystemTotalPhysicalMemory'] < 1 * _GB):
+    total_memory = tab.browser.platform.GetSystemTotalPhysicalMemory()
+    if total_memory is not None and total_memory < 1 * _GB:

[nednguyen, 2016/09/02 16:15:52]

Actually what do we do with this variable?

[perezju, 2016/09/03 10:05:43]

That seems to be it. Just skip the "zlib" test in the octane benchmark if the
platform does not have enough memory.

A bit more context of why the check was added:
https://codereview.chromium.org/450873002

I can see some alternatives:
- Remove the check entirely, and see whether this breaks or not on some devices
- Check for IsSvelte instead?

[nednguyen, 2016/09/03 11:43:05]

I see. Let's just keep this as-is to unblock your cleanup. 

       skipBenchmarks = '"zlib"'
     else:
       skipBenchmarks = ''