From b1f63863e873a76b13aa415d57b8bf5073ef8b6d Mon Sep 17 00:00:00 2001
From: Sotaro Ikeda <sotaro.ikeda.g@gmail.com>
Date: Tue, 19 Jul 2016 05:38:35 -0700
Subject: [PATCH] Bug 1287627 - Handle flush TextureHost without composition
 r=nical

---
 gfx/layers/Compositor.cpp | 13 +++++++++++++
 gfx/layers/Compositor.h   |  5 +++++
 2 files changed, 18 insertions(+)

diff --git a/gfx/layers/Compositor.cpp b/gfx/layers/Compositor.cpp
index d8690863c102..9c61be7ff116 100644
--- a/gfx/layers/Compositor.cpp
+++ b/gfx/layers/Compositor.cpp
@@ -55,6 +55,7 @@ void
 Compositor::EndFrame()
 {
   ReadUnlockTextures();
+  mLastCompositionEndTime = TimeStamp::Now();
 }
 
 void
@@ -78,6 +79,18 @@ Compositor::NotifyNotUsedAfterComposition(TextureHost* aTextureHost)
   MOZ_ASSERT(!mIsDestroyed);
 
   mNotifyNotUsedAfterComposition.AppendElement(aTextureHost);
+
+  // If Compositor holds many TextureHosts without compositing,
+  // the TextureHosts should be flushed to reduce memory consumption.
+  const int thresholdCount = 5;
+  const double thresholdSec = 2.0f;
+  if (mNotifyNotUsedAfterComposition.Length() > thresholdCount) {
+    TimeDuration duration = TimeStamp::Now() - mLastCompositionEndTime;
+    // Check if we could flush
+    if (duration.ToSeconds() > thresholdSec) {
+      FlushPendingNotifyNotUsed();
+    }
+  }
 }
 
 void
diff --git a/gfx/layers/Compositor.h b/gfx/layers/Compositor.h
index 5bc3cfd08dad..c6e301f3f625 100644
--- a/gfx/layers/Compositor.h
+++ b/gfx/layers/Compositor.h
@@ -593,6 +593,11 @@ protected:
    */
   nsTArray<RefPtr<TextureHost>> mNotifyNotUsedAfterComposition;
 
+  /**
+   * Last Composition end time.
+   */
+  TimeStamp mLastCompositionEndTime;
+
   /**
    * Render time for the current composition.
    */