Add multi-process GpuMemoryBuffer framework.

This adds a multi-process framework for reading/writing directly to
memory that the 3D graphics hardware can use for rendering without
any costly copying having to be done on the GPU process side.

A GpuMemoryBuffer is a type of shared memory that can be accessed
by the GPU. The high level procedure required to allocate this type
of memory is almost exactly the same as that for standard shared
memory. Only the browser process can allocated the memory and it
needs to be shared and registered with the GPU process before it can
be used.

This also adds a GpuMemoryBuffer type that is backed by standard
shared memory for testing purposes.

TEST=gpu_unittests --gtest_filter=MockGpuMemoryBufferTest.Lifecycle
BUG=261649

Review URL: https://codereview.chromium.org/19762004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230248 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 50 insertions, 4 deletions

diff --git a/content/common/gpu/client/command_buffer_proxy_impl.cc b/content/common/gpu/client/command_buffer_proxy_impl.cc
index 94abbe1..3fbe537 100644
--- a/content/common/gpu/client/command_buffer_proxy_impl.cc
+++ b/content/common/gpu/client/command_buffer_proxy_impl.cc
@@ -367,7 +367,7 @@ void CommandBufferProxyImpl::SetContextLostReason(
 }
 
 bool CommandBufferProxyImpl::SupportsGpuMemoryBuffer() {
-  return false;
+  return true;
 }
 
 gfx::GpuMemoryBuffer* CommandBufferProxyImpl::CreateGpuMemoryBuffer(
@@ -375,12 +375,58 @@ gfx::GpuMemoryBuffer* CommandBufferProxyImpl::CreateGpuMemoryBuffer(
     size_t height,
     unsigned internalformat,
     int32* id) {
-  NOTREACHED();
-  return NULL;
+  *id = -1;
+
+  if (last_state_.error != gpu::error::kNoError)
+    return NULL;
+
+  int32 new_id = channel_->ReserveGpuMemoryBufferId();
+  DCHECK(gpu_memory_buffers_.find(new_id) == gpu_memory_buffers_.end());
+
+  scoped_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer(
+      channel_->factory()->AllocateGpuMemoryBuffer(width,
+                                                   height,
+                                                   internalformat));
+  if (!gpu_memory_buffer)
+    return NULL;
+
+  DCHECK(GpuChannelHost::IsValidGpuMemoryBuffer(
+             gpu_memory_buffer->GetHandle()));
+
+  // This handle is owned by the GPU process and must be passed to it or it
+  // will leak. In otherwords, do not early out on error between here and the
+  // sending of the RegisterGpuMemoryBuffer IPC below.
+  gfx::GpuMemoryBufferHandle handle =
+      channel_->ShareGpuMemoryBufferToGpuProcess(
+          gpu_memory_buffer->GetHandle());
+
+  if (!Send(new GpuCommandBufferMsg_RegisterGpuMemoryBuffer(
+                route_id_,
+                new_id,
+                handle,
+                width,
+                height,
+                internalformat))) {
+    return NULL;
+  }
+
+  *id = new_id;
+  gpu_memory_buffers_[new_id] = gpu_memory_buffer.release();
+  return gpu_memory_buffers_[new_id];
 }
 
 void CommandBufferProxyImpl::DestroyGpuMemoryBuffer(int32 id) {
-  NOTREACHED();
+  if (last_state_.error != gpu::error::kNoError)
+    return;
+
+  // Remove the gpu memory buffer from the client side cache.
+  GpuMemoryBufferMap::iterator it = gpu_memory_buffers_.find(id);
+  if (it != gpu_memory_buffers_.end()) {
+    delete it->second;
+    gpu_memory_buffers_.erase(it);
+  }
+
+  Send(new GpuCommandBufferMsg_DestroyGpuMemoryBuffer(route_id_, id));
 }
 
 int CommandBufferProxyImpl::GetRouteID() const {