base: Increase hard limit for emulated discardable memory.

This increases the emulated discardable memory limit to 512MB by
setting the soft limit to 32MB and the hard limit expiration time
to 1 second.

BUG=383361,372158

Review URL: https://codereview.chromium.org/342943008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@281944 0039d316-1c4b-4281-b951-d872f2087c98

base/memory/discardable_memory_emulated.cc

@@ -10,18 +10,19 @@
 namespace base {
 namespace {
 
-// This is admittedly pretty magical. It's approximately enough memory for four
-// 2560x1600 images.
-const size_t kEmulatedMemoryLimit = 64 * 1024 * 1024;
-const size_t kEmulatedBytesToKeepUnderModeratePressure =
-    kEmulatedMemoryLimit / 4;
+// This is admittedly pretty magical.
+const size_t kEmulatedMemoryLimit = 512 * 1024 * 1024;
+const size_t kEmulatedSoftMemoryLimit = 32 * 1024 * 1024;
+const size_t kEmulatedBytesToKeepUnderModeratePressure = 4 * 1024 * 1024;
+const size_t kEmulatedHardMemoryLimitExpirationTimeMs = 1000;
 
 struct SharedState {
   SharedState()
       : manager(kEmulatedMemoryLimit,
-                kEmulatedMemoryLimit,
+                kEmulatedSoftMemoryLimit,
                 kEmulatedBytesToKeepUnderModeratePressure,
-                TimeDelta::Max()) {}
+                TimeDelta::FromMilliseconds(
+                    kEmulatedHardMemoryLimitExpirationTimeMs)) {}
 
   internal::DiscardableMemoryManager manager;
 };