Add support for GL_CHROMIUM_pixel_transfer_buffer_object.

gpu/command_buffer/service/buffer_manager.cc

Index: gpu/command_buffer/service/buffer_manager.cc
diff --git a/gpu/command_buffer/service/buffer_manager.cc b/gpu/command_buffer/service/buffer_manager.cc
index 864027dce48c38c395d63e2515069d09824ea45f..26c22e9adeebd5b2458c52ebbf4552cab2418670 100644
--- a/gpu/command_buffer/service/buffer_manager.cc
+++ b/gpu/command_buffer/service/buffer_manager.cc
@@ -79,7 +79,9 @@ BufferManager::BufferInfo::BufferInfo(BufferManager* manager, GLuint service_id)
       target_(0),
       size_(0),
       usage_(GL_STATIC_DRAW),
-      shadowed_(false) {
+      shadowed_(false),
+      shm_id_(0),
+      shm_offset_(0) {
   manager_->StartTracking(this);
 }
 
@@ -97,7 +99,9 @@ BufferManager::BufferInfo::~BufferInfo() {
 void BufferManager::BufferInfo::SetInfo(
     GLsizeiptr size, GLenum usage, bool shadow) {
   usage_ = usage;
-  if (size != size_ || shadow != shadowed_) {
+  shm_id_ = 0;
+  shm_offset_ = 0;
+  if (size != size_ || shadow != shadowed_ || decoder_.get()) {
     shadowed_ = shadow;
     size_ = size;
     ClearCache();
@@ -105,6 +109,24 @@ void BufferManager::BufferInfo::SetInfo(
       shadow_.reset(new int8[size]);
       memset(shadow_.get(), 0, size);
     }
+    decoder_.reset();
+  }
+}
+
+void BufferManager::BufferInfo::SetInfo(
+    GLsizeiptr size, GLenum usage, CommonDecoder* decoder, int32 shm_id,
+    uint32 shm_offset) {
+  usage_ = usage;
+  shm_id_ = shm_id;
+  shm_offset_ = shm_offset;
+  if (size != size_ || shadowed_ || decoder_.get() != decoder) {
+    size_ = size;
+    ClearCache();
+    if (shadowed_) {
+      shadow_.reset();
+      shadowed_ = false;
+    }
+    decoder_ = decoder->AsWeakPtr();
   }
 }
 
@@ -117,18 +139,31 @@ bool BufferManager::BufferInfo::SetRange(
     memcpy(shadow_.get() + offset, data, size);
     ClearCache();
   }
+  if (decoder_) {
+    int8* shm_data = decoder_->GetSharedMemoryAs<int8*>(

[greggman, 2012/05/24 20:56:00]

I'm confused. Why would you need to copy memory in set range? If the whole point
is that you're using shared memory so that client has already put the data in
the buffer. Am I mis-understanding

[reveman, 2012/05/25 15:45:10]

This is for when a client calls glBufferSubData, which should really be handled
on the client side. This can be removed once that's fixed.

+        shm_id_, shm_offset_, size_);
+    if (shm_data)
+      memcpy(shm_data + offset, data, size);
+  }
   return true;
 }
 
 const void* BufferManager::BufferInfo::GetRange(
     GLintptr offset, GLsizeiptr size) const {
-  if (!shadowed_) {
-    return NULL;
-  }
   if (offset < 0 || offset + size < offset || offset + size > size_) {
     return NULL;
   }
-  return shadow_.get() + offset;
+  if (shadowed_) {
+    return shadow_.get() + offset;
+  }
+  if (decoder_) {

[greggman, 2012/05/24 20:56:00]

If this is a shared memory buffer should this go before the shadowed_ check?

[reveman, 2012/05/25 15:45:10]

Doesn't really matter as making a buffer a shm buffer makes shadowed_ = false.

+    int8* shm_data = decoder_->GetSharedMemoryAs<int8*>(
+        shm_id_, shm_offset_, size_);
+    if (!shm_data)
+      return NULL;
+    return shm_data + offset;
+  }
+  return NULL;
 }
 
 void BufferManager::BufferInfo::ClearCache() {
@@ -228,6 +263,15 @@ void BufferManager::SetInfo(
   mem_represented_ += info->size();
 }
 
+void BufferManager::SetInfo(
+    BufferManager::BufferInfo* info, GLsizeiptr size, GLenum usage,
+    CommonDecoder* decoder, int32 shm_id, uint32 shm_offset) {
+  DCHECK(info);
+  mem_represented_ -= info->size();
+  info->SetInfo(size, usage, decoder, shm_id, shm_offset);
+  mem_represented_ += info->size();
+}
+
 bool BufferManager::SetTarget(BufferManager::BufferInfo* info, GLenum target) {
   // Check that we are not trying to bind it to a different target.
   if (info->target() != 0 && info->target() != target &&