cc: Route offscreen context creation for compositor to the browser.

content/common/gpu/client/offscreen_context.cc

Index: content/common/gpu/client/offscreen_context.cc
diff --git a/content/common/gpu/client/offscreen_context.cc b/content/common/gpu/client/offscreen_context.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5ab693edf6dbe1d721f1ed44e50bf8572e89a5f8
--- /dev/null
+++ b/content/common/gpu/client/offscreen_context.cc
@@ -0,0 +1,113 @@
+// Copyright (c) 2013 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 "content/common/gpu/client/offscreen_context.h"
+
+#include "third_party/skia/include/gpu/GrContext.h"
+#include "third_party/skia/include/gpu/gl/GrGLInterface.h"
+
+namespace content {
+
+OffscreenContext::OffscreenContext(OffscreenContextClient* client)
+    : client_(client) {
+}
+
+OffscreenContext::~OffscreenContext() {
+  if (gr_context_)
+    gr_context_->contextDestroyed();
+  if (context3d_) {
+    context3d_->setContextLostCallback(NULL);
+    context3d_->setMemoryAllocationChangedCallbackCHROMIUM(NULL);
+  }
+}
+
+WebKit::WebGraphicsContext3D* OffscreenContext::Context3d() {
+  if (context3d_)
+    return context3d_.get();
+
+  context3d_.reset(client_->CreateOffscreenContext());
+  if (context3d_ &&
+      (!context3d_->makeContextCurrent() ||
+       context3d_->getGraphicsResetStatusARB()))
+    context3d_.reset();
+
+  client_->DidCreateContext(this, !!context3d_);
+  if (!context3d_)
+    return NULL;
+
+  context3d_->setContextLostCallback(this);
+  // TODO(danakj): Talk to the GPU mem manager directly.
+  context3d_->setMemoryAllocationChangedCallbackCHROMIUM(this);
+  return context3d_.get();
+}
+
+static void BindWebGraphicsContext3DGLContextCallback(
+    const GrGLInterface* interface) {
+  reinterpret_cast<WebKit::WebGraphicsContext3D*>(
+      interface->fCallbackData)->makeContextCurrent();
+}
+
+GrContext* OffscreenContext::GrContext() {
+  if (gr_context_)
+    return gr_context_.get();
+
+  WebKit::WebGraphicsContext3D* context3d = Context3d();
+  if (!context3d)
+    return NULL;
+
+  skia::RefPtr<GrGLInterface> interface = skia::AdoptRef(
+      context3d->createGrGLInterface());
+  interface->fCallback = BindWebGraphicsContext3DGLContextCallback;
+  interface->fCallbackData =
+      reinterpret_cast<GrGLInterfaceCallbackData>(context3d);
+
+  gr_context_ = skia::AdoptRef(GrContext::Create(
+      kOpenGL_Shaders_GrEngine,
+      reinterpret_cast<GrPlatform3DContext>(interface.get())));
+  if (!gr_context_)
+    return NULL;
+
+  bool nonzero_allocation = true;
+  SetGaneshContextMemoryLimit(nonzero_allocation);
+  return gr_context_.get();
+}
+
+void OffscreenContext::SetGaneshContextMemoryLimit(
+    bool nonzero_allocation) {
+  if (!gr_context_)
+    return;
+
+  if (nonzero_allocation) {
+    gr_context_->setTextureCacheLimits(
+        kMaxGaneshTextureCacheCount, kMaxGaneshTextureCacheBytes);
+    return;
+  }
+  gr_context_->freeGpuResources();
+  gr_context_->setTextureCacheLimits(0, 0);
+}
+
+void OffscreenContext::onContextLost() {
+  // Save the contexts until the notifications are done, but requests for a
+  // context should create a new one.
+  scoped_ptr<WebKit::WebGraphicsContext3D> context3d =
+      context3d_.Pass();
+  if (context3d)
+    context3d->setMemoryAllocationChangedCallbackCHROMIUM(NULL);
+
+  skia::RefPtr<class GrContext> gr_context = gr_context_;
+  if (gr_context_) {
+    gr_context_->contextDestroyed();
+    gr_context_.clear();
+  }
+
+  client_->DidLoseContext(this);
+}
+
+// WebGraphicsMemoryAllocationChangedCallbackCHROMIUM implementation.
+void OffscreenContext::onMemoryAllocationChanged(
+    WebKit::WebGraphicsMemoryAllocation allocation) {
+  SetGaneshContextMemoryLimit(!!allocation.gpuResourceSizeInBytes);
+}
+
+}  // namespace content