Add GL_TEXTURE_EXTERNAL_OES as supported texture target for CHROMIUM_map_image.

ui/gl/gl_image_egl.cc

Index: ui/gl/gl_image_egl.cc
diff --git a/ui/gl/gl_image_egl.cc b/ui/gl/gl_image_egl.cc
index ddd2f6f5e29552cba3706e78fadae7d5951bbfb3..15b9fbf10c8f084ac023613db8208b511d9a6781 100644
--- a/ui/gl/gl_image_egl.cc
+++ b/ui/gl/gl_image_egl.cc
@@ -14,8 +14,8 @@ GLImageEGL::GLImageEGL(gfx::Size size)
       size_(size),
       release_after_use_(false),
       in_use_(false),
-      target_(0) {
-}
+      target_(0),
+      native_buffer_(0) {}
 
 GLImageEGL::~GLImageEGL() {
   Destroy();
@@ -23,16 +23,16 @@ GLImageEGL::~GLImageEGL() {
 
 bool GLImageEGL::Initialize(gfx::GpuMemoryBufferHandle buffer) {
   DCHECK(buffer.native_buffer);
+  native_buffer_ = buffer.native_buffer;

[reveman, 2014/03/19 18:17:30]

are you sure buffer.native_buffer is a valid pointer after this function
returns? Even if that happens to be the case, I'm not sure it's appropriate to
hold on to it here.

   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,
+                                 native_buffer_,
+                                 attrs);
 
   if (egl_image_ == EGL_NO_IMAGE_KHR) {
     EGLint error = eglGetError();
@@ -108,16 +108,22 @@ void GLImageEGL::DidUseTexImage() {
   if (!release_after_use_)
     return;
 
-  char zero[4] = { 0, };
-  glTexImage2D(target_,
-               0,
-               GL_RGBA,
-               1,
-               1,
-               0,
-               GL_RGBA,
-               GL_UNSIGNED_BYTE,
-               &zero);
+  EGLint attrs[] = {EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE, };
+  EGLImageKHR egl_image = eglCreateImageKHR(GLSurfaceEGL::GetHardwareDisplay(),
+                                            EGL_NO_CONTEXT,
+                                            EGL_NATIVE_BUFFER_ANDROID,
+                                            native_buffer_,
+                                            attrs);
+  DCHECK_NE(EGL_NO_IMAGE_KHR, egl_image)
+      << "Error creating EGLImage: " << eglGetError();
+  glEGLImageTargetTexture2DOES(target_, egl_image);

[reveman, 2014/03/19 18:17:30]

I don't understand why this would work. Binding the same native buffer again
releases it? Please explain how this works.

+  DCHECK_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+  EGLBoolean status =
+      eglDestroyImageKHR(GLSurfaceEGL::GetHardwareDisplay(), egl_image);

[boliu, 2014/03/20 10:57:29]

Currently this destroy fails.

+  if (status == EGL_FALSE) {
+    EGLint error = eglGetError();
+    LOG(ERROR) << "Error destroying EGLImage: " << error;
+  }
 }
 
 void GLImageEGL::WillModifyTexImage() {