Chromecast: Remove the notification of moderate memory pressure.

Sending the moderate memory pressure notification now has the same
effect on v8's garbage collection as sending critical memory pressure
notification, which will trigger immediate gargabe collection and cause
some unexpected (performance) side effect. Given that render_thread_impl
is already asking v8 periodically to do idle garbage collection, we
should remove the moderate memory pressure notification.

BUG=

Review URL: https://codereview.chromium.org/798043008

Cr-Commit-Position: refs/heads/master@{#312675}

1 files changed, 6 insertions, 13 deletions

diff --git a/chromecast/renderer/cast_content_renderer_client.cc b/chromecast/renderer/cast_content_renderer_client.cc
index 0e8e504..bbf456a 100644
--- a/chromecast/renderer/cast_content_renderer_client.cc
+++ b/chromecast/renderer/cast_content_renderer_client.cc
@@ -29,12 +29,11 @@ namespace shell {
 namespace {
 
 #if defined(ARCH_CPU_ARM_FAMILY) && !defined(OS_ANDROID)
-// These memory thresholds are set for Chromecast. See the UMA histogram
+// This memory threshold is set for Chromecast. See the UMA histogram
 // Platform.MeminfoMemFree when tuning.
 // TODO(gunsch): These should be platform/product-dependent. Look into a way
 // to move these to platform-specific repositories.
 const int kCriticalMinFreeMemMB = 24;
-const int kModerateMinFreeMemMB = 48;
 const int kPollingIntervalMS = 5000;
 
 void PlatformPollFreemem(void) {
@@ -46,17 +45,11 @@ void PlatformPollFreemem(void) {
     int free_mem_mb = static_cast<int64_t>(sys.freeram) *
         sys.mem_unit / (1024 * 1024);
 
-    if (free_mem_mb <= kModerateMinFreeMemMB) {
-      if (free_mem_mb <= kCriticalMinFreeMemMB) {
-        // Memory is getting really low, we need to do whatever we can to
-        // prevent deadlocks and interfering with other processes.
-        base::MemoryPressureListener::NotifyMemoryPressure(
-            base::MemoryPressureListener::MEMORY_PRESSURE_CRITICAL);
-      } else {
-        // There is enough memory, but it is starting to get low.
-        base::MemoryPressureListener::NotifyMemoryPressure(
-            base::MemoryPressureListener::MEMORY_PRESSURE_MODERATE);
-      }
+    if (free_mem_mb <= kCriticalMinFreeMemMB) {
+      // Memory is getting really low, we need to do whatever we can to
+      // prevent deadlocks and interfering with other processes.
+      base::MemoryPressureListener::NotifyMemoryPressure(
+          base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL);
     }
   }