Initial commit of the blimp/ folder and target

blimp/client/compositor/blimp_output_surface.cc

Index: blimp/client/compositor/blimp_output_surface.cc
diff --git a/blimp/client/compositor/blimp_output_surface.cc b/blimp/client/compositor/blimp_output_surface.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9fdd69a672be2c46efe0235ab2f183f8450153ca
--- /dev/null
+++ b/blimp/client/compositor/blimp_output_surface.cc
@@ -0,0 +1,31 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "blimp/client/compositor/blimp_output_surface.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "cc/output/output_surface_client.h"
+#include "gpu/command_buffer/client/context_support.h"
+
+namespace blimp {
+
+BlimpOutputSurface::BlimpOutputSurface(
+    const scoped_refptr<cc::ContextProvider>& context_provider)
+    : cc::OutputSurface(context_provider), weak_factory_(this) {
+  capabilities_.max_frames_pending = 2;
+}
+
+BlimpOutputSurface::~BlimpOutputSurface() {}
+
+void BlimpOutputSurface::SwapBuffers(cc::CompositorFrame* frame) {
+  context_provider_->ContextSupport()->Swap();
+  client_->DidSwapBuffers();

[Wez, 2015/08/27 18:23:55]

nit: Comment to clarify what these calls are actually doing, e.g. presumably the
first one actually swaps things and the second is some sort of feedback to an
internal object of cc::OutputSurface? Why do we need to call DidSwapBuffers()
anyway - why doesn't OutputSurface::OnSwapBuffersComplete do that?

[David Trainor- moved to gerrit, 2015/08/28 01:23:47]

The comment on the interface is pretty clear about what we have to do.  I'm just
implementing at per those instructions (one line of code - after the change
below - per step in the interface comment).  I'll add a "see
cc::OutputSurface::SwapBuffers for details" if you'd like.

+
+  base::MessageLoop::current()->task_runner()->PostTask(

[Wez, 2015/08/27 18:23:55]

nit: Add a comment to indicate why we need to PostTask this, rather than calling
immediately?

[David Trainor- moved to gerrit, 2015/08/28 01:23:47]

It's the advice I got when discussing how to implement this.  I'll investigate
for details for why.  Also changed this to just use
cc::OutputSurface::PostSwapBuffersComplete.

+      FROM_HERE, base::Bind(&BlimpOutputSurface::OnSwapBuffersComplete,
+                            weak_factory_.GetWeakPtr()));
+}
+
+}  // namespace blimp