Making use of bindless variants mailbox produce/consume on remainders.

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index d249a2f472054b60ac0151cc12d55f93c1e7e43f..382b955a3328487c7d87fa9be060ed3df3085d7a 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -2365,23 +2365,12 @@ void GLRenderer::GetFramebufferPixelsAsync(
     bool own_mailbox = !request->has_texture_mailbox();
 
     GLuint texture_id = 0;
-    gl_->GenTextures(1, &texture_id);
-
     gpu::Mailbox mailbox;
     if (own_mailbox) {
       GLC(gl_, gl_->GenMailboxCHROMIUM(mailbox.name));
-    } else {
-      mailbox = request->texture_mailbox().mailbox();
-      DCHECK_EQ(static_cast<unsigned>(GL_TEXTURE_2D),
-                request->texture_mailbox().target());
-      DCHECK(!mailbox.IsZero());
-      unsigned incoming_sync_point = request->texture_mailbox().sync_point();
-      if (incoming_sync_point)
-        GLC(gl_, gl_->WaitSyncPointCHROMIUM(incoming_sync_point));
-    }
+      gl_->GenTextures(1, &texture_id);
+      GLC(gl_, gl_->BindTexture(GL_TEXTURE_2D, texture_id));
 
-    GLC(gl_, gl_->BindTexture(GL_TEXTURE_2D, texture_id));
-    if (own_mailbox) {
       GLC(gl_,
           gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
       GLC(gl_,
@@ -2394,16 +2383,26 @@ void GLRenderer::GetFramebufferPixelsAsync(
               GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
       GLC(gl_, gl_->ProduceTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name));
     } else {
-      GLC(gl_, gl_->ConsumeTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name));
+      mailbox = request->texture_mailbox().mailbox();
+      DCHECK_EQ(static_cast<unsigned>(GL_TEXTURE_2D),
+                request->texture_mailbox().target());
+      DCHECK(!mailbox.IsZero());
+      unsigned incoming_sync_point = request->texture_mailbox().sync_point();
+      if (incoming_sync_point)
+        GLC(gl_, gl_->WaitSyncPointCHROMIUM(incoming_sync_point));
+
+      texture_id = GLC(
+          gl_,
+          gl_->CreateAndConsumeTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name));
     }
     GetFramebufferTexture(texture_id, RGBA_8888, window_rect);
-    GLC(gl_, gl_->BindTexture(GL_TEXTURE_2D, 0));
 
     unsigned sync_point = gl_->InsertSyncPointCHROMIUM();
     TextureMailbox texture_mailbox(mailbox, GL_TEXTURE_2D, sync_point);
 
     scoped_ptr<SingleReleaseCallback> release_callback;
     if (own_mailbox) {
+      GLC(gl_, gl_->BindTexture(GL_TEXTURE_2D, 0));

[danakj, 2014/07/08 15:51:30]

FWIW GetFramebufferTexture already binds/unbinds, so I'm not sure what to do
with this. It's fine here, or it could move below the produce, or it could go
away, idk, just pointing it out.

[dshwang, 2014/07/08 16:36:16]

GetFramebufferTexture actually call BindTexture(GL_TEXTURE_2D, 0) at the end of
fuction. So it's not really needed now.
So we can remove this line, but someone might be wonder why we don't unbind the
texture against line 2372.

If we move this line above GetFramebufferTexture, it hits perf adversely,
because GetFramebufferTexture bind the texture again.

gles2_helper skipped redundant texture binding, so I remains this line for
readability.

Do you want to remove this line?

[danakj, 2014/07/08 16:40:25]

I like having something here to show it's unbound since we did a bind above, so
let's keep it, i was just thinking aloud.

       release_callback = texture_mailbox_deleter_->GetReleaseCallback(
           output_surface_->context_provider(), texture_id);
     } else {