Stop suspending renderer and changing purge interval to 20min

chrome/browser/memory/tab_manager.cc

Index: chrome/browser/memory/tab_manager.cc
diff --git a/chrome/browser/memory/tab_manager.cc b/chrome/browser/memory/tab_manager.cc
index b6062ab348a7fc4de577743cd6eddddf47e7aff5..6c2cf66a1aba3f71310e4e3317e849839d3b0e0b 100644
--- a/chrome/browser/memory/tab_manager.cc
+++ b/chrome/browser/memory/tab_manager.cc
@@ -86,7 +86,7 @@ const int kSuspendThresholdSeconds = kAdjustmentIntervalSeconds * 4;
 
 // A suspended renderer is suspended for this duration.
 constexpr base::TimeDelta kDurationOfRendererSuspension =
-    base::TimeDelta::FromSeconds(120);
+    base::TimeDelta::FromSeconds(1200);

[bashi, 2017/01/13 02:11:42]

We no longer suspend renderers. Shouldn't we change the name of this const and
related flags? I understand the cost of renaming as it affects a lot of things
including experiments, but I'd prefer avoiding confusions.

I think it's fine to rename this in follow-up CLs.

[tasak, 2017/01/13 03:27:04]

Acknowledged.
But currelty it is difficult to rename this, because there is no way to purge
cache except changing MC state from NORMAL to SUSPENDED.

[bashi, 2017/01/13 04:36:23]

Yeah, currently it's difficult to rename as purging is depend on
MemoryCoordinatorClient::OnMemoryStateChange(). However at least we should stop
using "suspend" outside memory coordinator (and clients). We can rename
variables and functions in RenderThreadImpl. (Though we still call
base::MemoryCoordinatorClientRegistry::GetInstance()->Notify(base::MemoryState::SUSPENDED)).

 
 // A resumed renderer is resumed for this duration.
 constexpr base::TimeDelta kDurationOfRendererResumption =