Mailbox support for texture layers.

cc/texture_layer.cc

Index: cc/texture_layer.cc
diff --git a/cc/texture_layer.cc b/cc/texture_layer.cc
index 36c4220371d6f5653a7dedae16ed17b414504f96..3592ef85a91009d782615a2c9eef48c5a01463ba 100644
--- a/cc/texture_layer.cc
+++ b/cc/texture_layer.cc
@@ -14,12 +14,18 @@ namespace cc {
 
 scoped_refptr<TextureLayer> TextureLayer::create(TextureLayerClient* client)
 {
-    return scoped_refptr<TextureLayer>(new TextureLayer(client));
+    return scoped_refptr<TextureLayer>(new TextureLayer(client, false));
 }
 
-TextureLayer::TextureLayer(TextureLayerClient* client)
+scoped_refptr<TextureLayer> TextureLayer::createMailboxLayer()
+{
+    return scoped_refptr<TextureLayer>(new TextureLayer(0, true));
+}
+
+TextureLayer::TextureLayer(TextureLayerClient* client, bool mailboxLayer)
     : Layer()
     , m_client(client)
+    , m_mailboxLayer(mailboxLayer)
     , m_flipped(true)
     , m_uvRect(0, 0, 1, 1)
     , m_premultipliedAlpha(true)
@@ -42,11 +48,13 @@ TextureLayer::~TextureLayer()
         if (m_rateLimitContext && m_client)
             layerTreeHost()->stopRateLimiter(m_client->context());
     }
+    if (!m_contentCommitted && m_mailboxName.size())
+        m_mailboxReleaseCallback.Run(0);
 }
 
 scoped_ptr<LayerImpl> TextureLayer::createLayerImpl(LayerTreeImpl* treeImpl)
 {
-    return TextureLayerImpl::create(treeImpl, m_layerId).PassAs<LayerImpl>();
+    return TextureLayerImpl::create(treeImpl, m_layerId, m_mailboxLayer).PassAs<LayerImpl>();
 }
 
 void TextureLayer::setFlipped(bool flipped)
@@ -92,6 +100,7 @@ void TextureLayer::setRateLimitContext(bool rateLimit)
 
 void TextureLayer::setTextureId(unsigned id)
 {
+    DCHECK(!m_mailboxLayer);
     if (m_textureId == id)
         return;
     if (m_textureId && layerTreeHost())
@@ -100,6 +109,19 @@ void TextureLayer::setTextureId(unsigned id)
     setNeedsCommit();
 }
 
+void TextureLayer::setTextureMailbox(const std::string& mailboxName, const base::Callback<void(unsigned)>& callback)
+{
+    DCHECK(m_mailboxLayer);

[danakj, 2013/01/02 16:17:22]

Can we DCHECK that mailboxName.isempty == callback.isnull?

+    if (m_mailboxName.compare(mailboxName) == 0)
+        return;
+    // If we never commited the mailbox, we need to release it here
+    if (!m_contentCommitted && m_mailboxName.size())
+        m_mailboxReleaseCallback.Run(0);
+    m_mailboxReleaseCallback = callback;
+    m_mailboxName = mailboxName;
+    setNeedsCommit();
+}
+
 void TextureLayer::willModifyTexture()
 {
     if (layerTreeHost() && (drawsContent() || m_contentCommitted)) {
@@ -125,7 +147,7 @@ void TextureLayer::setLayerTreeHost(LayerTreeHost* host)
 
 bool TextureLayer::drawsContent() const
 {
-    return (m_client || m_textureId) && !m_contextLost && Layer::drawsContent();
+    return (m_client || m_textureId || m_mailboxName.size()) && !m_contextLost && Layer::drawsContent();
 }
 
 void TextureLayer::update(ResourceUpdateQueue& queue, const OcclusionTracker*, RenderingStats&)
@@ -147,7 +169,10 @@ void TextureLayer::pushPropertiesTo(LayerImpl* layer)
     textureLayer->setUVRect(m_uvRect);
     textureLayer->setVertexOpacity(m_vertexOpacity);
     textureLayer->setPremultipliedAlpha(m_premultipliedAlpha);
-    textureLayer->setTextureId(m_textureId);
+    if (m_mailboxLayer)
+        textureLayer->setTextureMailbox(m_mailboxName, m_mailboxReleaseCallback);
+    else
+        textureLayer->setTextureId(m_textureId);
     m_contentCommitted = drawsContent();
 }