Copy NV12 picture buffers on demand on the main thread.

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 9640 matching lines @@
                                       gl::GLImage* image) {
   // Note: We update the state to COPIED prior to calling CopyTexImage()
   // as that allows the GLImage implemenatation to set it back to UNBOUND
   // and ensure that CopyTexImage() is called each time the texture is
   // used.
   texture->SetLevelImageState(textarget, 0, Texture::COPIED);
   bool rv = image->CopyTexImage(textarget);
   DCHECK(rv) << "CopyTexImage() failed";
 }
 
 void GLES2DecoderImpl::DoCopyTexImageIfNeeded(Texture* texture,

[sandersd (OOO until July 31), 2017/05/23 23:23:31]

Perhaps this needs a new name? (Please update the comment on line 1923 in either
case.)

                                               GLenum textarget) {
   // Image is already in use if texture is attached to a framebuffer.
   if (texture && !texture->IsAttachedToFramebuffer()) {
     Texture::ImageState image_state;
     gl::GLImage* image = texture->GetLevelImage(textarget, 0, &image_state);
     if (image && image_state == Texture::UNBOUND) {
       ScopedGLErrorSuppressor suppressor(
           "GLES2DecoderImpl::DoCopyTexImageIfNeeded", GetErrorState());
       glBindTexture(textarget, texture->service_id());
-      DoCopyTexImage(texture, textarget, image);
+      if (image->BindTexImage(textarget)) {
+        image_state = Texture::BOUND;
+      } else {
+        DoCopyTexImage(texture, textarget, image);
+      }
       RestoreCurrentTextureBindings(&state_, textarget);
     }
   }
 }
 
 void GLES2DecoderImpl::DoCopyBufferSubData(GLenum readtarget,
                                            GLenum writetarget,
                                            GLintptr readoffset,
                                            GLintptr writeoffset,
                                            GLsizeiptr size) {
@@ skipping 44 matching lines @@
 
         if (textarget != GL_TEXTURE_CUBE_MAP) {
           Texture* texture = texture_ref->texture();
           Texture::ImageState image_state;
           gl::GLImage* image =
               texture->GetLevelImage(textarget, 0, &image_state);
           if (image && image_state == Texture::UNBOUND &&
               !texture->IsAttachedToFramebuffer()) {
             ScopedGLErrorSuppressor suppressor(
                 "GLES2DecoderImpl::PrepareTexturesForRender", GetErrorState());
+            glActiveTexture(GL_TEXTURE0 + texture_unit_index);
+            if (image->BindTexImage(textarget)) {

[sandersd (OOO until July 31), 2017/05/23 23:23:31]

This is same as the core of DoCopyTexImageIfNeeded(). Can
DoCopyTexImageIfNeeded() be reduce or refactored to share the implementation?

+              image_state = Texture::BOUND;
+            } else {
+              DoCopyTexImage(texture, textarget, image);
+            }
             textures_set = true;
-            glActiveTexture(GL_TEXTURE0 + texture_unit_index);
-            DoCopyTexImage(texture, textarget, image);
             continue;
           }
         }
       }
       // else: should this be an error?
     }
   }
   return !textures_set;
 }
 
@@ skipping 9976 matching lines @@
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu