Allow WebExternalTextureLayers to receive a bitmap along with a mailbox

webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc

Index: webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc
diff --git a/webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc b/webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc
index eb06faf7f5f2a5704e43ba8266709830484bd672..bc2ac4f0a61718daeb66f70160c52a06e80d7855 100644
--- a/webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc
+++ b/webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc
@@ -10,6 +10,7 @@
 #include "third_party/WebKit/public/platform/WebExternalTextureMailbox.h"
 #include "third_party/WebKit/public/platform/WebFloatRect.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
+#include "webkit/renderer/compositor_bindings/web_external_bitmap_impl.h"
 #include "webkit/renderer/compositor_bindings/web_layer_impl.h"
 
 using cc::TextureLayer;
@@ -109,9 +110,16 @@ WebKit::WebGraphicsContext3D* WebExternalTextureLayerImpl::Context3d() {
 }
 
 bool WebExternalTextureLayerImpl::PrepareTextureMailbox(
-    cc::TextureMailbox* mailbox) {
+    cc::TextureMailbox* mailbox,
+    bool use_shared_memory) {
   WebKit::WebExternalTextureMailbox client_mailbox;
-  if (!client_->prepareMailbox(&client_mailbox)) {
+  WebExternalBitmapImpl* bitmap = NULL;
+
+  if (use_shared_memory)
+    bitmap = AllocateBitmap();
+  if (!client_->prepareMailbox(&client_mailbox, bitmap)) {
+    if (bitmap)
+      free_bitmaps_.push_back(bitmap);
     return false;
   }
   gpu::Mailbox name;
@@ -119,22 +127,44 @@ bool WebExternalTextureLayerImpl::PrepareTextureMailbox(
   cc::TextureMailbox::ReleaseCallback callback =
       base::Bind(&WebExternalTextureLayerImpl::DidReleaseMailbox,
                  this->AsWeakPtr(),
-                 client_mailbox);
-  *mailbox = cc::TextureMailbox(name, callback, client_mailbox.syncPoint);
+                 client_mailbox,
+                 bitmap);
+  if (bitmap) {
+    *mailbox =
+        cc::TextureMailbox(bitmap->getSharedMemory(), bitmap->size(), callback);
+  } else {
+    *mailbox = cc::TextureMailbox(name, callback, client_mailbox.syncPoint);
+  }
   return true;
 }
 
+WebExternalBitmapImpl* WebExternalTextureLayerImpl::AllocateBitmap() {
+  if (!free_bitmaps_.empty()) {
+    WebExternalBitmapImpl* result = free_bitmaps_.back();
+    free_bitmaps_.weak_erase(free_bitmaps_.end() - 1);
+    return result;
+  }
+  return new WebExternalBitmapImpl;
+}
+
+// static
 void WebExternalTextureLayerImpl::DidReleaseMailbox(
+    base::WeakPtr<WebExternalTextureLayerImpl> layer,
     const WebKit::WebExternalTextureMailbox& mailbox,
+    WebExternalBitmapImpl* bitmap,
     unsigned sync_point,
     bool lost_resource) {
-  if (lost_resource)
+  if (lost_resource || !layer) {
+    delete bitmap;
     return;
+  }
 
   WebKit::WebExternalTextureMailbox available_mailbox;
   memcpy(available_mailbox.name, mailbox.name, sizeof(available_mailbox.name));
   available_mailbox.syncPoint = sync_point;
-  client_->mailboxReleased(available_mailbox);
+  if (bitmap)
+    layer->free_bitmaps_.push_back(bitmap);
+  layer->client_->mailboxReleased(available_mailbox);
 }
 
 }  // namespace webkit