skia: Added chrome implementation of SkDiscardableMemory.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index b1e4a71cd6f45b9dc28a548327e822d2537c0098..868c62f796b688d792fe5de8d0655c306f2acdf4 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -90,6 +90,8 @@
 #include "media/filters/gpu_video_decoder_factories.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
+#include "skia/ext/sk_discardable_memory_chrome.h"
+#include "third_party/skia/include/core/SkGraphics.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/web/WebColorName.h"
 #include "third_party/WebKit/public/web/WebDatabase.h"
@@ -414,6 +416,9 @@ void RenderThreadImpl::Init() {
   memory_pressure_listener_.reset(new base::MemoryPressureListener(
       base::Bind(&RenderThreadImpl::OnMemoryPressure, base::Unretained(this))));
 
+  SkGraphics::SetSkDiscardableMemoryFactory(
+      skia::SkDiscardableMemoryFactoryChrome::GetInstance());
+
   TRACE_EVENT_END_ETW("RenderThreadImpl::Init", 0, "");
 }