Mailbox support for texture layers.

cc/texture_layer_impl.cc

Index: cc/texture_layer_impl.cc
diff --git a/cc/texture_layer_impl.cc b/cc/texture_layer_impl.cc
index 433ce34256e7260b5bdf10b9c573d56420e729d2..1d546164ba2c0827c23c85174b3cf9c1ad17120b 100644
--- a/cc/texture_layer_impl.cc
+++ b/cc/texture_layer_impl.cc
@@ -5,19 +5,22 @@
 #include "cc/texture_layer_impl.h"
 
 #include "base/stringprintf.h"
+#include "cc/layer_tree_impl.h"
 #include "cc/quad_sink.h"
 #include "cc/renderer.h"
 #include "cc/texture_draw_quad.h"
 
 namespace cc {
 
-TextureLayerImpl::TextureLayerImpl(LayerTreeImpl* treeImpl, int id)
+TextureLayerImpl::TextureLayerImpl(LayerTreeImpl* treeImpl, int id, bool usesMailbox)
     : LayerImpl(treeImpl, id)
     , m_textureId(0)
     , m_externalTextureResource(0)
     , m_premultipliedAlpha(true)
     , m_flipped(true)
     , m_uvRect(0, 0, 1, 1)
+    , m_hasPendingMailbox(false)
+    , m_usesMailbox(usesMailbox)
 {
   m_vertexOpacity[0] = 1.0f;
   m_vertexOpacity[1] = 1.0f;
@@ -27,14 +30,50 @@ TextureLayerImpl::TextureLayerImpl(LayerTreeImpl* treeImpl, int id)
 
 TextureLayerImpl::~TextureLayerImpl()
 {
+    if (m_externalTextureResource) {
+        DCHECK(m_usesMailbox);
+        ResourceProvider* provider = layerTreeImpl()->resource_provider();
+        provider->deleteResource(m_externalTextureResource);
+    }
+    if (m_hasPendingMailbox && !m_pendingMailboxName.empty())
+        m_pendingMailboxReleaseCallback.Run(0);
+}
+
+void TextureLayerImpl::setTextureMailbox(const std::string& mailboxName, const base::Callback<void(unsigned)>& releaseCallback)
+{
+    DCHECK(m_usesMailbox);
+    // Same mailbox name was commited, nothing to do.
+    if (m_pendingMailboxName.compare(mailboxName) == 0)
+        return;
+    // Two commits without a draw, ack the previous mailbox.
+    if (m_hasPendingMailbox && !m_pendingMailboxReleaseCallback.is_null())
+        m_pendingMailboxReleaseCallback.Run(0);
+
+    m_pendingMailboxName = mailboxName;
+    m_hasPendingMailbox = true;
+    m_pendingMailboxReleaseCallback = releaseCallback;
 }
 
 void TextureLayerImpl::willDraw(ResourceProvider* resourceProvider)
 {
-    if (!m_textureId)
+    if (!m_usesMailbox) {
+        if (!m_textureId)
+            return;
+        DCHECK(!m_externalTextureResource);
+        m_externalTextureResource = resourceProvider->createResourceFromExternalTexture(m_textureId);
         return;
-    DCHECK(!m_externalTextureResource);
-    m_externalTextureResource = resourceProvider->createResourceFromExternalTexture(m_textureId);
+    }
+
+    if (!m_hasPendingMailbox)
+        return;
+
+    if (m_externalTextureResource) {
+        resourceProvider->deleteResource(m_externalTextureResource);
+        m_externalTextureResource = 0;
+    }
+    if (!m_pendingMailboxName.empty())
+        m_externalTextureResource = resourceProvider->createResourceFromTextureMailbox(m_pendingMailboxName, m_pendingMailboxReleaseCallback);
+    m_hasPendingMailbox = false;
 }
 
 void TextureLayerImpl::appendQuads(QuadSink& quadSink, AppendQuadsData& appendQuadsData)
@@ -59,6 +98,8 @@ void TextureLayerImpl::appendQuads(QuadSink& quadSink, AppendQuadsData& appendQu
 
 void TextureLayerImpl::didDraw(ResourceProvider* resourceProvider)
 {
+    if (m_usesMailbox)
+        return;
     if (!m_externalTextureResource)
         return;
     // FIXME: the following assert will not be true when sending resources to a