Copy NV12 picture buffers on demand on the main thread.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 49f4fc74411d1b356bb200102ce74d7f6bac8861..28d762cf5328fd9d460da9d93393302b833dc1ed 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -1919,9 +1919,15 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   // state of |texture| is updated to reflect the new state.
   void DoCopyTexImage(Texture* texture, GLenum textarget, gl::GLImage* image);
 
-  // This will call DoCopyTexImage if texture has an image but that image is
-  // not bound or copied to the texture.
-  void DoCopyTexImageIfNeeded(Texture* texture, GLenum textarget);
+  // If the texture has an image but that image is not bound or copied to the
+  // texture, this will first attempt to bind it, and if that fails
+  // DoCopyTexImage on it. texture_unit is the texture unit it should be bound
+  // to, or 0 if it doesn't matter - setting it to 0 will cause the previous
+  // binding to be restored after the operation. This returns true if a copy
+  // or bind happened.
+  bool DoBindOrCopyTexImageIfNeeded(Texture* texture,
+                                    GLenum textarget,
+                                    GLuint texture_unit);
 
   // Returns false if textures were replaced.
   bool PrepareTexturesForRender();
@@ -7780,7 +7786,7 @@ void GLES2DecoderImpl::DoFramebufferTexture2DCommon(
   }
 
   if (texture_ref)
-    DoCopyTexImageIfNeeded(texture_ref->texture(), textarget);
+    DoBindOrCopyTexImageIfNeeded(texture_ref->texture(), textarget, 0);
 
   std::vector<GLenum> attachments;
   if (attachment == GL_DEPTH_STENCIL_ATTACHMENT) {
@@ -9658,20 +9664,30 @@ void GLES2DecoderImpl::DoCopyTexImage(Texture* texture,
   DCHECK(rv) << "CopyTexImage() failed";
 }
 
-void GLES2DecoderImpl::DoCopyTexImageIfNeeded(Texture* texture,
-                                              GLenum textarget) {
+bool GLES2DecoderImpl::DoBindOrCopyTexImageIfNeeded(Texture* texture,
+                                                    GLenum textarget,
+                                                    GLuint texture_unit) {
   // 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());
+          "GLES2DecoderImpl::DoBindOrCopyTexImageIfNeeded", GetErrorState());
+      if (texture_unit)
+        glActiveTexture(texture_unit);
       glBindTexture(textarget, texture->service_id());

[Zhenyao Mo, 2017/05/25 17:21:58]

I am still concerned. Here we changed the tex binding for textture_unit, but
never restore it.  Won't this be problematic?

It's not your CL causing this, but since you are working on it, it would be nice
to just fix it.

-      DoCopyTexImage(texture, textarget, image);
-      RestoreCurrentTextureBindings(&state_, textarget);
+      if (image->BindTexImage(textarget)) {
+        image_state = Texture::BOUND;
+      } else {
+        DoCopyTexImage(texture, textarget, image);
+      }
+      if (!texture_unit)
+        RestoreCurrentTextureBindings(&state_, textarget);
+      return true;
     }
   }
+  return false;
 }
 
 void GLES2DecoderImpl::DoCopyBufferSubData(GLenum readtarget,
@@ -9726,16 +9742,9 @@ bool GLES2DecoderImpl::PrepareTexturesForRender() {
 
         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());
+          if (DoBindOrCopyTexImageIfNeeded(texture, textarget,
+                                           GL_TEXTURE0 + texture_unit_index)) {
             textures_set = true;
-            glActiveTexture(GL_TEXTURE0 + texture_unit_index);
-            DoCopyTexImage(texture, textarget, image);
             continue;
           }
         }
@@ -16947,7 +16956,7 @@ void GLES2DecoderImpl::DoCopyTextureCHROMIUM(
       return;
   }
 
-  DoCopyTexImageIfNeeded(source_texture, source_target);
+  DoBindOrCopyTexImageIfNeeded(source_texture, source_target, 0);
 
   // GL_TEXTURE_EXTERNAL_OES texture requires that we apply a transform matrix
   // before presenting.
@@ -17159,7 +17168,7 @@ void GLES2DecoderImpl::DoCopySubTextureCHROMIUM(
     }
   }
 
-  DoCopyTexImageIfNeeded(source_texture, source_target);
+  DoBindOrCopyTexImageIfNeeded(source_texture, source_target, 0);
 
   // GL_TEXTURE_EXTERNAL_OES texture requires apply a transform matrix
   // before presenting.
@@ -17357,7 +17366,7 @@ void GLES2DecoderImpl::DoCompressedCopyTextureCHROMIUM(GLuint source_id,
       "gpu",
       "GLES2DecoderImpl::DoCompressedCopyTextureCHROMIUM, fallback");
 
-  DoCopyTexImageIfNeeded(source_texture, source_texture->target());
+  DoBindOrCopyTexImageIfNeeded(source_texture, source_texture->target(), 0);
 
   // As a fallback, copy into a non-compressed GL_RGBA texture.
   LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER(kFunctionName);