gpu: Refactor GpuMemoryBuffer framework for multi-process support.

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 cbf7c17a335c9d14ac3fa27bc849d3209aae99e0..6304f7773da5d59d3c8b8efd8f36fdef30c09005 100644
--- a/ui/gl/gl_image_shm.cc
+++ b/ui/gl/gl_image_shm.cc
@@ -10,7 +10,9 @@
 
 namespace gfx {
 
-GLImageShm::GLImageShm(gfx::Size size) : size_(size) {
+GLImageShm::GLImageShm(const gfx::Size& size, unsigned internalformat)
+    : size_(size),
+      internalformat_(internalformat) {
 }
 
 GLImageShm::~GLImageShm() {
@@ -40,8 +42,26 @@ bool GLImageShm::BindTexImage() {
   TRACE_EVENT0("gpu", "GLImageShm::BindTexImage");
   DCHECK(shared_memory_);
 
-  const int kBytesPerPixel = 4;
-  size_t size = size_.GetArea() * kBytesPerPixel;
+  GLenum format;
+  GLenum type;
+  int bytes_per_pixel;
+  switch (internalformat_) {
+    case GL_RGBA:
+      format = GL_RGBA;
+      type = GL_UNSIGNED_BYTE;
+      bytes_per_pixel = 4;
+      break;
+    case GL_BGRA_EXT:
+      format = GL_BGRA_EXT;
+      type = GL_UNSIGNED_BYTE;
+      bytes_per_pixel = 4;
+      break;
+    default:
+      NOTREACHED();

[piman, 2013/08/01 21:19:30]

nit: this comes from the (untrusted) client side. While we don't expose this
cross-process yet, I'm pretty sure we won't go back and audit everything. So I'm
not sure NOTREACHED() is really what we want (false sense of security etc.),
though we can certainly DVLOG.

[reveman, 2013/08/08 23:19:00]

Good point. Fixed in latest patch.

+      return false;
+  }
+
+  size_t size = size_.GetArea() * bytes_per_pixel;
   DCHECK(!shared_memory_->memory());
   if (!shared_memory_->Map(size)) {
     DVLOG(0) << "Failed to map shared memory.";
@@ -51,12 +71,12 @@ bool GLImageShm::BindTexImage() {
   DCHECK(shared_memory_->memory());
   glTexImage2D(GL_TEXTURE_2D,
                0,  // mip level
-               GL_RGBA,
+               internalformat_,
                size_.width(),
                size_.height(),
                0,  // border
-               GL_RGBA,
-               GL_UNSIGNED_BYTE,
+               format,
+               type,
                shared_memory_->memory());
 
   shared_memory_->Unmap();