android: Define 1GB-4GB Android devices as partial low-end (#9276)

Introduce a new device memory classification for Cobalt on Android TV.
Devices with 1GB to 4GB of physical memory are now considered
"mid-range" or "partial low-end" devices.

This change enables the PartialLowEndModeOnMidRangeDevices feature
for these devices, triggering optimizations such as limiting media
players to improve performance and stability on memory-constrained
Android TV hardware. The feature is enabled by default unless
an explicit low-end device mode is active.

Issue: 488101349

Author: borongc

base/system/sys_info.cc

@@ -103,9 +103,28 @@ bool IsAndroid4GbOr6GbDevice() {
   return is_4gb_or_6g_device;
 }
 
+#if BUILDFLAG(IS_COBALT)
+bool IsATVMidRangeDevice() {
+  // For Cobalt on Android TV, we consider > 1GB and <= 4GB devices as mid-range
+  // to trigger partial low-end mode optimizations (e.g. limiting media players).
+  constexpr int kLowerBoundMB = 1 * 1024;
+  constexpr int kUpperBoundMB = 4 * 1024;
+  static bool is_mid_range_device =
+      kLowerBoundMB < base::SysInfo::AmountOfPhysicalMemoryMB() &&
+      base::SysInfo::AmountOfPhysicalMemoryMB() <= kUpperBoundMB;
+  return is_mid_range_device;
+}
+#endif
+
 bool IsPartialLowEndModeOnMidRangeDevicesEnabled() {
   // TODO(crbug.com/1434873): make the feature not enable on 32-bit devices
   // before launching or going to high Stable %.
+#if BUILDFLAG(IS_COBALT)
+  if (IsATVMidRangeDevice()) {
+    return base::FeatureList::IsEnabled(
+             features::kPartialLowEndModeOnMidRangeDevices);
+  }
+#endif  // BUILDFLAG(IS_COBALT)
   return IsAndroid4GbOr6GbDevice() &&
          base::FeatureList::IsEnabled(
              features::kPartialLowEndModeOnMidRangeDevices);

cobalt/android/apk/app/src/main/java/dev/cobalt/util/JavaSwitches.java

@@ -89,6 +89,8 @@ public static List<String> getExtraCommandLineArgs(Map<String, String> javaSwitc
       if (javaSwitches.containsKey(JavaSwitches.ENABLE_LOW_END_DEVICE_MODE_NO_SIMULATED_MEMORY)) {
         extraCommandLineArgs.add("--enable-low-end-device-mode-no-simulated-memory");
       }
+    } else {
+      extraCommandLineArgs.add("--enable-features=PartialLowEndModeOnMidRangeDevices");
     }
 
     if (javaSwitches.containsKey(JavaSwitches.CC_LAYER_TREE_OPTIMIZATION)) {