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

cc/grcontext_provider.cc

Index: cc/grcontext_provider.cc
diff --git a/cc/grcontext_provider.cc b/cc/grcontext_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..11664b8efa00c4f090a05d71b2ba68f3843dd6ab
--- /dev/null
+++ b/cc/grcontext_provider.cc
@@ -0,0 +1,114 @@
+// Copyright 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 "cc/grcontext_provider.h"
+
+#include "cc/resource_provider.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 cc {
+
+GrContextProvider::GrContextProvider() : context3d_(NULL) {}
+
+GrContextProvider::~GrContextProvider() {
+  if (gr_context_)
+    gr_context_->contextDestroyed();
+}
+
+static void BindWebGraphicsContext3DGLContextCallback(
+    const GrGLInterface* interface) {
+  reinterpret_cast<WebKit::WebGraphicsContext3D*>(
+      interface->fCallbackData)->makeContextCurrent();
+}
+
+void GrContextProvider::SetContext3d(
+    WebKit::WebGraphicsContext3D* context3d) {
+  if (context3d == context3d_)
+    return;
+  context3d_ = context3d;
+  if (gr_context_)
+    gr_context_->contextDestroyed();
+  gr_context_.clear();
+
+  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_Shaders_GrEngine,
+      reinterpret_cast<GrPlatform3DContext>(interface.get())));
+
+  if (!gr_context_)
+    return;
+
+  // TODO(danakj): Register the callback with content/.
+  // TODO(danakj): Talk to the GPU mem manager directly.
+  context3d_->setMemoryAllocationChangedCallbackCHROMIUM(this);
+
+  bool nonzero_allocation = true;
+  SetGaneshContextMemoryLimit(nonzero_allocation);
+}
+
+void GrContextProvider::SetGaneshContextMemoryLimit(bool nonzero_allocation) {
+  if (!gr_context_)
+    return;
+
+  if (nonzero_allocation) {
+    // The limit of the number of textures we hold in the GrContext's
+    // bitmap->texture cache.
+    const int kMaxGaneshTextureCacheCount = 2048;
+    // The limit of the bytes allocated toward textures in the GrContext's
+    // bitmap->texture cache.
+    const size_t kMaxGaneshTextureCacheBytes = 96 * 1024 * 1024;
+
+    gr_context_->setTextureCacheLimits(
+        kMaxGaneshTextureCacheCount, kMaxGaneshTextureCacheBytes);
+    return;
+  }
+  gr_context_->freeGpuResources();
+  gr_context_->setTextureCacheLimits(0, 0);
+}
+
+// WebGraphicsMemoryAllocationChangedCallbackCHROMIUM implementation.
+void GrContextProvider::onMemoryAllocationChanged(
+    WebKit::WebGraphicsMemoryAllocation allocation) {
+  SetGaneshContextMemoryLimit(!!allocation.gpuResourceSizeInBytes);
+}
+
+GrContextProvider::ScopedContexts::ScopedContexts(
+    GrContextProvider* grcontext_provider)
+    : grcontext_provider_(grcontext_provider) {
+}
+
+GrContextProvider::ScopedContexts::~ScopedContexts() {}
+
+GrContextProvider::ScopedContextsFlushed::ScopedContextsFlushed(
+    ResourceProvider* resource_provider,
+    GrContextProvider* grcontext_provider)
+    : ScopedContexts(grcontext_provider) {
+  resource_provider->flush();
+}
+
+GrContextProvider::ScopedContextsFlushed::~ScopedContextsFlushed() {
+  // Flush gr context so that all the rendered stuff appears on the
+  // texture.
+  if (gr_context())
+    gr_context()->flush();
+  // Flush the GL context so rendering results from this context are
+  // visible in the compositor's context.
+  if (context3d())
+    context3d()->flush();
+}
+
+}  // namespace cc