Add GL_TEXTURE_EXTERNAL_OES as supported texture target for CHROMIUM_map_image.

ui/gl/gl_image_shm.cc

Index: ui/gl/gl_image_shm.cc
diff --git a/ui/gl/gl_image_shm.cc b/ui/gl/gl_image_shm.cc
index 076b1fcb79379acb8e21d8fa2481d645500e4179..01bff0ced8684395800a27d0abcbb58e022c555b 100644
--- a/ui/gl/gl_image_shm.cc
+++ b/ui/gl/gl_image_shm.cc
@@ -6,7 +6,7 @@
 
 #include "base/debug/trace_event.h"
 #include "base/process/process_handle.h"
-#include "ui/gl/gl_bindings.h"
+#include "ui/gl/scoped_binders.h"
 
 namespace gfx {
 
@@ -64,8 +64,9 @@ GLenum BytesPerPixel(unsigned internalformat) {
 
 GLImageShm::GLImageShm(gfx::Size size, unsigned internalformat)
     : size_(size),
-      internalformat_(internalformat) {
-}
+      internalformat_(internalformat),
+      external_texture_id_(0),

[reveman, 2014/03/18 10:41:04]

nit: 0u

+      egl_image_(EGL_NO_IMAGE_KHR) {}
 
 GLImageShm::~GLImageShm() {
   Destroy();
@@ -95,7 +96,34 @@ bool GLImageShm::Initialize(gfx::GpuMemoryBufferHandle buffer) {
   return true;
 }
 
+void GLImageShm::SetGLParameters() {
+  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);
+}

[reveman, 2014/03/18 10:41:04]

I'd remove this utility function. Just makes the code harder to read IMO.
There's at least no need for it to be a member function.

+
+bool GLImageShm::CreateEGLImage() {

[reveman, 2014/03/18 10:41:04]

I'm not sure this utility function is worth much either. If you really want it,
please make it a non-member function with input/output parameters.

+  EGLint egl_attrib_list[] = {EGL_GL_TEXTURE_LEVEL_KHR, 0,  // mip-level.
+                              EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE};
+  egl_image_ =
+      eglCreateImageKHR(eglGetCurrentDisplay(),
+                        eglGetCurrentContext(),
+                        EGL_GL_TEXTURE_2D_KHR,
+                        reinterpret_cast<EGLClientBuffer>(external_texture_id_),
+                        egl_attrib_list);
+  if (egl_image_ == EGL_NO_IMAGE_KHR) {

[reveman, 2014/03/18 10:41:04]

To keep things simple, could this just be:
DCHECK_NE(EGL_NO_IMAGE_KHR, egl_image_) << "Error creating EGLImage: " << error;

+    EGLint error = eglGetError();
+    LOG(ERROR) << "Error creating EGLImage: " << error;
+    return false;
+  }
+  return true;
+}
+
 void GLImageShm::Destroy() {
+  if (egl_image_ != EGL_NO_IMAGE_KHR)
+    eglDestroyImageKHR(eglGetCurrentDisplay(), egl_image_);
+  if (external_texture_id_)
+    glDeleteTextures(1, &external_texture_id_);
 }
 
 gfx::Size GLImageShm::GetSize() {
@@ -114,17 +142,44 @@ bool GLImageShm::BindTexImage(unsigned target) {
     return false;
   }
 
-  DCHECK(shared_memory_->memory());
-  glTexImage2D(target,
-               0,  // mip level
-               TextureFormat(internalformat_),
-               size_.width(),
-               size_.height(),
-               0,  // border
-               DataFormat(internalformat_),
-               DataType(internalformat_),
-               shared_memory_->memory());
-
+  if (target != GL_TEXTURE_EXTERNAL_OES) {
+    DCHECK(shared_memory_->memory());

[reveman, 2014/03/18 10:41:04]

move this DCHECK above so it doesn't have to be duplicated.

+    glTexImage2D(target,
+                 0,  // mip level
+                 TextureFormat(internalformat_),
+                 size_.width(),
+                 size_.height(),
+                 0,  // border
+                 DataFormat(internalformat_),
+                 DataType(internalformat_),
+                 shared_memory_->memory());
+  } else {
+    if (!external_texture_id_)
+      glGenTextures(1, &external_texture_id_);
+
+    ScopedTextureBinder texture_binder(GL_TEXTURE_2D, external_texture_id_);
+    SetGLParameters();
+
+    DCHECK(shared_memory_->memory());
+    glTexImage2D(GL_TEXTURE_2D,
+                 0,  // mip level
+                 TextureFormat(internalformat_),
+                 size_.width(),
+                 size_.height(),
+                 0,  // border
+                 DataFormat(internalformat_),
+                 DataType(internalformat_),
+                 shared_memory_->memory());
+
+    if (!egl_image_) {
+      if (!CreateEGLImage()) {
+        shared_memory_->Unmap();
+        return false;
+      }
+    }
+    glBindTexture(GL_TEXTURE_2D, external_texture_id_);
+    glEGLImageTargetTexture2DOES(target, egl_image_);
+  }
   shared_memory_->Unmap();
   return true;
 }