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..2a6447d43d316c877f68338ee2522d5ade026cd1 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 +30,51 @@ 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) {
+        DCHECK(!resourceProvider->inUseByConsumer(m_externalTextureResource));

[piman, 2013/01/08 02:01:52]

This check may not be true with ubercomp (because the resource may not be back
from the parent yet), however it's also not needed, since if the resource is
still in use, it'll just be marked for deletion, the deletion itself (and the
callback) will happen once the texture comes back from the parent.

[alexst (slow to review), 2013/01/08 02:46:27]

Done.

+        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 +99,8 @@ 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