[Experiment] purge-and-suspend

cc/tiles/software_image_decode_controller.cc

Index: cc/tiles/software_image_decode_controller.cc
diff --git a/cc/tiles/software_image_decode_controller.cc b/cc/tiles/software_image_decode_controller.cc
index 4d0ca7e851711a6583bb48517264e029ec11555c..3a5f6017bf1cde0146f69a8c4cd29acb7ac9e8a2 100644
--- a/cc/tiles/software_image_decode_controller.cc
+++ b/cc/tiles/software_image_decode_controller.cc
@@ -10,6 +10,7 @@
 #include <algorithm>
 #include <functional>
 
+#include "base/allocator/allocator_extension.h"
 #include "base/format_macros.h"
 #include "base/macros.h"
 #include "base/memory/discardable_memory.h"
@@ -154,6 +155,9 @@ SoftwareImageDecodeController::SoftwareImageDecodeController(
         this, "cc::SoftwareImageDecodeController",
         base::ThreadTaskRunnerHandle::Get());
   }
+  memory_pressure_listener_.reset(new base::MemoryPressureListener(
+      base::Bind(&SoftwareImageDecodeController::OnMemoryPressure,
+                 base::Unretained(this))));
 }
 
 SoftwareImageDecodeController::~SoftwareImageDecodeController() {
@@ -700,6 +704,13 @@ bool SoftwareImageDecodeController::OnMemoryDump(
   return true;
 }
 
+void SoftwareImageDecodeController::OnMemoryPressure(
+    base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
+  decoded_images_.Clear();
+  at_raster_decoded_images_.Clear();
+  base::allocator::ReleaseFreeMemory();
+}
+
 void SoftwareImageDecodeController::DumpImageMemoryForCache(
     const ImageMRUCache& cache,
     const char* cache_name,