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

webkit/gpu/grcontext_for_webgraphicscontext3d.cc

+// 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 "webkit/gpu/grcontext_for_webgraphicscontext3d.h"
+
+#include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
+#include "third_party/skia/include/gpu/GrContext.h"
+#include "third_party/skia/include/gpu/gl/GrGLInterface.h"
+
+namespace webkit {
+namespace gpu {
+
+// The limit of the number of textures we hold in the GrContext's
+// bitmap->texture cache.
+static const int kMaxGaneshTextureCacheCount = 2048;
+// The limit of the bytes allocated toward textures in the GrContext's
+// bitmap->texture cache.
+static const size_t kMaxGaneshTextureCacheBytes = 96 * 1024 * 1024;
+
+static void BindWebGraphicsContext3DGLContextCallback(
+    const GrGLInterface* interface) {
+  reinterpret_cast<WebKit::WebGraphicsContext3D*>(
+      interface->fCallbackData)->makeContextCurrent();
+}
+
+GrContextForWebGraphicsContext3D::GrContextForWebGraphicsContext3D(
+    WebKit::WebGraphicsContext3D* context3d) {
+  if (!context3d)
+    return;
+
+  skia::RefPtr<GrGLInterface> interface = skia::AdoptRef(
+      context3d->createGrGLInterface());
+  if (!interface)
+    return;
+
+  interface->fCallback = BindWebGraphicsContext3DGLContextCallback;
+  interface->fCallbackData =
+      reinterpret_cast<GrGLInterfaceCallbackData>(context3d);
+
+  gr_context_ = skia::AdoptRef(GrContext::Create(
+      kOpenGL_GrBackend,
+      reinterpret_cast<GrBackendContext>(interface.get())));
+  if (!gr_context_)
+    return;
+
+  bool nonzero_allocation = true;
+  SetMemoryLimit(nonzero_allocation);
+}
+
+GrContextForWebGraphicsContext3D::~GrContextForWebGraphicsContext3D() {
+  if (gr_context_)
+    gr_context_->contextDestroyed();
+}
+
+void GrContextForWebGraphicsContext3D::SetMemoryLimit(bool nonzero_allocation) {
+  if (!gr_context_)
+    return;
+
+  if (nonzero_allocation) {
+    gr_context_->setTextureCacheLimits(
+        kMaxGaneshTextureCacheCount, kMaxGaneshTextureCacheBytes);
+    return;
+  }
+  gr_context_->freeGpuResources();
+  gr_context_->setTextureCacheLimits(0, 0);
+}
+
+}  // namespace gpu
+}  // namespace webkit