Hook up CSSPaintValue::image to CSS Paint API callback.

third_party/WebKit/Source/modules/csspaint/CSSPaintDefinition.cpp

 // Copyright 2016 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 "modules/csspaint/CSSPaintDefinition.h"
 
 #include "bindings/core/v8/ScriptState.h"
+#include "bindings/core/v8/V8Binding.h"
+#include "bindings/core/v8/V8BindingMacros.h"
+#include "core/dom/ExecutionContext.h"
+#include "core/frame/ConsoleTypes.h"
+#include "core/inspector/ConsoleMessage.h"
+#include "modules/csspaint/Geometry.h"
+#include "modules/csspaint/PaintRenderingContext2D.h"
+#include "platform/ScriptForbiddenScope.h"
+#include "platform/graphics/ImageBuffer.h"
+#include "platform/graphics/PaintGeneratedImage.h"
+#include "platform/graphics/RecordingImageBufferSurface.h"
+#include "platform/graphics/UnacceleratedImageBufferSurface.h"
 
 namespace blink {
 
+namespace {
+
+// TODO(ikilpatrick): Modify RecordingImageBufferSurface so that it cannot

[chrishtr, 2016/04/06 18:55:20]

Cannot fall back, or has a required un-accelerated mode? Don't you
simply require an un-accelerated surface?

[ikilpatrick, 2016/04/07 23:03:00]

At the moment when you invoke RecordingImageBufferSurface#getPicture it can
potentially fallback to a UnaccelleratedImageBufferSurface for a few reasons (it
assumes that it'll be reused, always has a prev/next frame).

See:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

I've talked with junov@ about modifying RecordingIBS to prevent this, then this
can disappear.

+// fallback to a UnacceleratedImageBufferSurface.
+class UnacceleratedSurfaceFactory : public RecordingImageBufferFallbackSurfaceFactory {
+public:
+    virtual PassOwnPtr<ImageBufferSurface> createSurface(const IntSize& size, OpacityMode opacityMode)
+    {
+        return adoptPtr(new UnacceleratedImageBufferSurface(size, opacityMode));
+    }
+
+    virtual ~UnacceleratedSurfaceFactory() { }
+};
+
+static void clearHandle(const v8::WeakCallbackInfo<ScopedPersistent<v8::Object>>& data)
+{
+    data.GetParameter()->clear();
+}
+
+} // namespace
+
 RawPtr<CSSPaintDefinition> CSSPaintDefinition::create(ScriptState* scriptState, v8::Local<v8::Function> constructor, v8::Local<v8::Function> paint)
 {
     return new CSSPaintDefinition(scriptState, constructor, paint);
 }
 
 CSSPaintDefinition::CSSPaintDefinition(ScriptState* scriptState, v8::Local<v8::Function> constructor, v8::Local<v8::Function> paint)
     : m_scriptState(scriptState)
     , m_constructor(scriptState->isolate(), constructor)
     , m_paint(scriptState->isolate(), paint)
 {
 }
 
 CSSPaintDefinition::~CSSPaintDefinition()
 {
 }
 
+PassRefPtr<Image> CSSPaintDefinition::paint(const IntSize& size)
+{
+    v8::Isolate* isolate = m_scriptState->isolate();
+
+    ScriptState::Scope scope(m_scriptState.get());
+    v8::MicrotasksScope microtasksScope(isolate, v8::MicrotasksScope::kRunMicrotasks);
+
+    v8::Local<v8::Object> instance = m_instance.newLocal(m_scriptState->isolate());
+    if (isUndefinedOrNull(instance))
+        return nullptr;
+
+    PaintRenderingContext2D* renderingContext = PaintRenderingContext2D::create(
+        ImageBuffer::create(adoptPtr(new RecordingImageBufferSurface(size, adoptPtr(new UnacceleratedSurfaceFactory())))));
+    Geometry* geom = Geometry::create(size);
+
+    v8::Local<v8::Value> argv[] = {
+        toV8(renderingContext, m_scriptState->context()->Global(), isolate),
+        toV8(geom, m_scriptState->context()->Global(), isolate)
+    };
+
+    v8::Local<v8::Function> paint = m_paint.newLocal(isolate);
+
+    ScriptForbiddenScope::AllowUserAgentScript allowScripting;
+    v8::TryCatch block(isolate);
+
+    V8ScriptRunner::callFunction(paint, m_scriptState->getExecutionContext(), instance, 2, argv, isolate);
+
+    if (block.HasCaught()) {
+        block.ReThrow();
+        return nullptr;
+    }
+
+    return PaintGeneratedImage::create(renderingContext->imageBuffer()->getPicture(), size);
+}
+
+v8::Local<v8::Object> CSSPaintDefinition::paintInstance()
+{
+    v8::Isolate* isolate = m_scriptState->isolate();
+
+    ScriptState::Scope scope(m_scriptState.get());
+    v8::MicrotasksScope microtasksScope(isolate, v8::MicrotasksScope::kDoNotRunMicrotasks);
+
+    if (m_instance.isEmpty()) {
+        v8::Local<v8::Function> constructor = m_constructor.newLocal(isolate);
+        ASSERT(!isUndefinedOrNull(constructor));
+
+        v8::Local<v8::Object> paintInstance;
+        v8::TryCatch block(isolate);
+        if (!v8Call(constructor->NewInstance(m_scriptState->context()), paintInstance, block)) {
+            m_scriptState->getExecutionContext()->addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, "Failed to create instance of class."));
+        } else {
+            m_instance.set(isolate, paintInstance);
+            m_instance.setWeak(&m_instance, clearHandle);
+        }
+
+        return paintInstance;
+    }
+
+    return m_instance.newLocal(isolate);
+}
+
 } // namespace blink