Add GL_TEXTURE_EXTERNAL_OES as supported texture target for CHROMIUM_map_image.

ui/gl/gl_image_egl.cc

 // Copyright (c) 2013 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 "ui/gl/gl_image_egl.h"
 
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_surface_egl.h"
+#include "ui/gl/scoped_binders.h"
 
 namespace gfx {
 
 GLImageEGL::GLImageEGL(gfx::Size size)
     : egl_image_(EGL_NO_IMAGE_KHR),
       size_(size),
       release_after_use_(false),
       in_use_(false),
-      target_(0) {
-}
+      target_(0),
+      egl_image_for_unbind_(EGL_NO_IMAGE_KHR),
+      texture_id_for_unbind_(0) {}
 
 GLImageEGL::~GLImageEGL() {
   Destroy();
 }
 
 bool GLImageEGL::Initialize(gfx::GpuMemoryBufferHandle buffer) {
   DCHECK(buffer.native_buffer);
   EGLint attrs[] = {
     EGL_IMAGE_PRESERVED_KHR, EGL_TRUE,
     EGL_NONE,
   };
-  egl_image_ = eglCreateImageKHR(
-      GLSurfaceEGL::GetHardwareDisplay(),
-      EGL_NO_CONTEXT,
-      EGL_NATIVE_BUFFER_ANDROID,
-      buffer.native_buffer,
-      attrs);
+  egl_image_ = eglCreateImageKHR(GLSurfaceEGL::GetHardwareDisplay(),
+                                 EGL_NO_CONTEXT,
+                                 EGL_NATIVE_BUFFER_ANDROID,
+                                 buffer.native_buffer,
+                                 attrs);
 
   if (egl_image_ == EGL_NO_IMAGE_KHR) {
     EGLint error = eglGetError();
     LOG(ERROR) << "Error creating EGLImage: " << error;
     return false;
   }
 
   return true;
 }
 
 void GLImageEGL::Destroy() {
-  if (egl_image_ == EGL_NO_IMAGE_KHR)
-    return;
-
-  EGLBoolean success = eglDestroyImageKHR(
-      GLSurfaceEGL::GetHardwareDisplay(), egl_image_);
-
-  if (success == EGL_FALSE) {
-    EGLint error = eglGetError();
-    LOG(ERROR) << "Error destroying EGLImage: " << error;
+  if (egl_image_ != EGL_NO_IMAGE_KHR) {
+    EGLBoolean success =
+        eglDestroyImageKHR(GLSurfaceEGL::GetHardwareDisplay(), egl_image_);
+    if (success == EGL_FALSE)
+      LOG(ERROR) << "Error destroying EGLImage: " << eglGetError();
+    egl_image_ = EGL_NO_IMAGE_KHR;
   }
 
-  egl_image_ = EGL_NO_IMAGE_KHR;
+  if (egl_image_for_unbind_ != EGL_NO_IMAGE_KHR) {
+    EGLBoolean success =
+        eglDestroyImageKHR(eglGetCurrentDisplay(), egl_image_for_unbind_);

[reveman, 2014/03/22 12:38:57]

does this need to be GLSurfaceEGL::GetHardwareDisplay()? is it possible that a
display is not current when Destory is called? For consistency, I prefer if you
used GetHardwareDisplay() here and everywhere else where you currently use
eglGetCurrentDisplay(). If you can't use GetHardwareDisplay(), please explain
why.

+    if (success == EGL_FALSE)
+      LOG(ERROR) << "Error destroying EGLImage: " << eglGetError();
+    egl_image_for_unbind_ = EGL_NO_IMAGE_KHR;
+  }
+
+  if (texture_id_for_unbind_) {
+    glDeleteTextures(1, &texture_id_for_unbind_);
+    texture_id_for_unbind_ = 0;
+  }
 }
 
 gfx::Size GLImageEGL::GetSize() {
   return size_;
 }
 
 bool GLImageEGL::BindTexImage(unsigned target) {
   if (egl_image_ == EGL_NO_IMAGE_KHR) {
     LOG(ERROR) << "NULL EGLImage in BindTexImage";
     return false;
@@ skipping 32 matching lines @@
   DCHECK_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
 }
 
 void GLImageEGL::DidUseTexImage() {
   DCHECK(in_use_);
   in_use_ = false;
 
   if (!release_after_use_)
     return;
 
-  char zero[4] = { 0, };
-  glTexImage2D(target_,
-               0,
-               GL_RGBA,
-               1,
-               1,
-               0,
-               GL_RGBA,
-               GL_UNSIGNED_BYTE,
-               &zero);
+  if (egl_image_for_unbind_ == EGL_NO_IMAGE_KHR) {
+    DCHECK_EQ(0u, texture_id_for_unbind_);
+    glGenTextures(1, &texture_id_for_unbind_);
+
+    ScopedTextureBinder texture_binder(GL_TEXTURE_2D, texture_id_for_unbind_);

[reveman, 2014/03/22 12:38:57]

I assume this is only needed until glTexImage2D is called. Can you add a scope
here to make that explicit?

+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+    char zero[4] = {0, };
+    glTexImage2D(
+        GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, &zero);
+
+    EGLint attrs[] = {EGL_GL_TEXTURE_LEVEL_KHR, 0,  // mip-level.
+                      EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE};
+    egl_image_for_unbind_ = eglCreateImageKHR(
+        eglGetCurrentDisplay(),

[reveman, 2014/03/22 12:38:57]

GLSurfaceEGL::GetHardwareDisplay() if possible

+        eglGetCurrentContext(),

[reveman, 2014/03/22 12:38:57]

EGL_NO_CONTEXT if possible?

+        EGL_GL_TEXTURE_2D_KHR,
+        reinterpret_cast<EGLClientBuffer>(texture_id_for_unbind_),
+        attrs);
+    DCHECK_NE(EGL_NO_IMAGE_KHR, egl_image_for_unbind_)
+        << "Error creating EGLImage: " << eglGetError();
+  }
+
+  glEGLImageTargetTexture2DOES(target_, egl_image_for_unbind_);
+  DCHECK_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
 }
 
 void GLImageEGL::WillModifyTexImage() {
 }
 
 void GLImageEGL::DidModifyTexImage() {
 }
 
 void GLImageEGL::SetReleaseAfterUse() {
   release_after_use_ = true;
 }
 
 }  // namespace gfx