cc: Add zero-copy texture update support to delegating renderer.

cc/resources/resource_provider.cc

Index: cc/resources/resource_provider.cc
diff --git a/cc/resources/resource_provider.cc b/cc/resources/resource_provider.cc
index 9b03b675571ed3e7da55f64ab83f16eafc7a6ba2..11f4eae8c4d29f4bcbd5e0ee16f466c3a13a6cdc 100644
--- a/cc/resources/resource_provider.cc
+++ b/cc/resources/resource_provider.cc
@@ -1194,6 +1194,11 @@ void ResourceProvider::ReceiveReturnsFromParent(
     if (resource->exported_count)
       continue;
 
+    // Need to wait for the current read lock fence to pass before we can
+    // recycle this resource.
+    if (resource->enable_read_lock_fences)
+      resource->read_lock_fence = current_read_lock_fence_;
+
     if (resource->gl_id) {
       if (returned.sync_point)
         GLC(gl, gl->WaitSyncPointCHROMIUM(returned.sync_point));
@@ -1251,6 +1256,8 @@ void ResourceProvider::TransferResource(GLES2Interface* gl,
   resource->filter = source->filter;
   resource->size = source->size;
 
+  LazyCreate(source);

[danakj, 2014/01/16 17:55:52]

Why this? You're transferring a resource that has never been allocated/written
to?

[piman, 2014/01/16 21:54:34]

I don't think it's correct here, actually.
This would create a new texture id for an imported or external resource, but not
even Consume the mailbox into it, so we're in a limbo state where we have a
texture id and a mailbox, but they don't correspond to each other.

Maybe this should move into the "else if (!source->mailbox.IsValid())" block
below, gated by source->image_id ?

[reveman, 2014/01/17 01:38:39]

We've created and written to the GLImage but it has not yet been bound to a
texture so there hasn't been a need to create the texture. This is in part to be
nice to android_webview where we need to delay GL commands until draw time.

[reveman, 2014/01/17 01:38:39]

Hm, is texture_pool not 0 in those cases? Makes sense to move it to the "else if
(!source->mailbox.IsValid())" block anyhow but I'd rather not have it gated by
"source->image_id" and instead make sure LazyCreate does the right thing here
and not mess with imported/external resources.

+
   if (source->shared_bitmap) {
     resource->mailbox = source->shared_bitmap->id();
     resource->is_software = true;
@@ -1259,12 +1266,20 @@ void ResourceProvider::TransferResource(GLES2Interface* gl,
     // Don't set a sync point, the caller will do it.
     DCHECK(source->gl_id);
     GLC(gl, gl->BindTexture(resource->target, source->gl_id));
+    if (source->image_id) {
+      DCHECK(source->dirty_image);
+      BindImageForSampling(source);
+    }
     GLC(gl, gl->GenMailboxCHROMIUM(resource->mailbox.name));
     GLC(gl,
         gl->ProduceTextureCHROMIUM(resource->target, resource->mailbox.name));
     source->mailbox.SetName(resource->mailbox);
   } else {
     DCHECK(source->mailbox.IsTexture());
+    if (source->image_id && source->dirty_image) {

[piman, 2014/01/16 21:54:34]

Add a DCHECK(source->gl_id);
The only reason we'd get here (we have a mailbox and an image_id) is if we
already sent the resource at least once (it can't be imported or external), in
which case, we'd have created the texture in the previous block the first time
around.

[reveman, 2014/01/17 01:38:39]

Done.

+      GLC(gl, gl->BindTexture(resource->target, source->gl_id));
+      BindImageForSampling(source);
+    }
     // This is either an external resource, or a compositor resource that we
     // already exported. Make sure to forward the sync point that we were given.
     resource->mailbox = source->mailbox.name();
@@ -1497,14 +1512,8 @@ GLenum ResourceProvider::BindForSampling(
     resource->filter = filter;
   }
 
-  if (resource->image_id && resource->dirty_image) {
-    // Release image currently bound to texture.
-    if (resource->bound_image_id)
-      gl->ReleaseTexImage2DCHROMIUM(target, resource->bound_image_id);
-    gl->BindTexImage2DCHROMIUM(target, resource->image_id);
-    resource->bound_image_id = resource->image_id;
-    resource->dirty_image = false;
-  }
+  if (resource->image_id && resource->dirty_image)
+    BindImageForSampling(resource);
 
   return target;
 }
@@ -1696,6 +1705,19 @@ void ResourceProvider::LazyAllocate(Resource* resource) {
   }
 }
 
+void ResourceProvider::BindImageForSampling(Resource* resource) {
+  GLES2Interface* gl = ContextGL();
+  DCHECK(resource->gl_id);
+  DCHECK(resource->image_id);
+
+  // Release image currently bound to texture.
+  if (resource->bound_image_id)
+    gl->ReleaseTexImage2DCHROMIUM(resource->target, resource->bound_image_id);
+  gl->BindTexImage2DCHROMIUM(resource->target, resource->image_id);
+  resource->bound_image_id = resource->image_id;
+  resource->dirty_image = false;
+}
+
 void ResourceProvider::EnableReadLockFences(ResourceProvider::ResourceId id,
                                             bool enable) {
   Resource* resource = GetResource(id);