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..5f12025179c05b1b04b6273ee3d16f28ccdcb5ae 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/gl_surface_egl.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),
+      egl_image_(EGL_NO_IMAGE_KHR) {}
 
 GLImageShm::~GLImageShm() {
   Destroy();
@@ -96,6 +97,10 @@ bool GLImageShm::Initialize(gfx::GpuMemoryBufferHandle buffer) {
 }
 
 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 +119,65 @@ 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());
+    glTexImage2D(target,
+                 0,  // mip level
+                 TextureFormat(internalformat_),
+                 size_.width(),
+                 size_.height(),
+                 0,  // border
+                 DataFormat(internalformat_),
+                 DataType(internalformat_),
+                 shared_memory_->memory());
+  } else {
+    glGenTextures(1, &external_texture_id_);

[reveman, 2014/03/14 14:06:22]

Why did you make external_texture_id_ a member but still only use it locally?
Can't you reuse the external_texture_id_ and the egl_image_ between each call to
BindTexImage? That's why I suggested you make them members.

[sohanjg, 2014/03/15 10:03:53]

Done.
Have reused the creation code.
But, they cant be created once and reused between BindTexImage calls. I release
them at the end, so it shouldnt leak.

+
+    // Save current GL states
+    GLint current_texture_id = 0;
+    glGetIntegerv(GL_TEXTURE_BINDING_EXTERNAL_OES, &current_texture_id);
+    GLint current_active_texture_unit = 0;
+    glGetIntegerv(GL_ACTIVE_TEXTURE, &current_active_texture_unit);

[reveman, 2014/03/14 14:06:22]

Do you have to change active texture?

[sohanjg, 2014/03/15 10:03:53]

Done.
Generally before bindTex we do an activeTex during creation of texture. But,
here the old tex unit is also GL_TEXTURE0.

+
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, external_texture_id_);
+    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);
+
+    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());
+
+    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) {
+      EGLint error = eglGetError();
+      LOG(ERROR) << "Error creating EGLImage: " << error;
+      shared_memory_->Unmap();
+      return false;
+    }
+    glBindTexture(GL_TEXTURE_2D, external_texture_id_);
+    glEGLImageTargetTexture2DOES(target, egl_image_);
+
+    // Restore GL States and release
+    Destroy();

[reveman, 2014/03/14 14:06:22]

Destory is supposed to release all resources. Not just some. You can't use it
here.

[sohanjg, 2014/03/15 10:03:53]

Done.
Added a new ReleaseEGLImageandTexture function to do it.

+    glBindTexture(target, current_texture_id);
+    glActiveTexture(current_active_texture_unit);
+  }
   shared_memory_->Unmap();
   return true;
 }