Add "alpha" option to PaintWorklet

third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.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/PaintWorkletGlobalScope.h"
 
 #include "bindings/core/v8/V8BindingMacros.h"
 #include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/CSSPropertyNames.h"
 #include "core/css/parser/CSSVariableParser.h"
@@ skipping 71 matching lines @@
                 // Disallow prefixes.
                 if (property[0] == '-') {
                     addConsoleMessage(ConsoleMessage::create(JSMessageSource, WarningMessageLevel, property + " is a prefixed property which is not supported."));
                 } else {
                     nativeInvalidationProperties.append(propertyID);
                 }
             }
         }
     }
 
+    // Parse 'alpha' AKA hasAlphaChannel property.
+    v8::Local<v8::Value> alphaValue;
+    if (!v8Call(constructor->Get(context, v8String(isolate, "alpha")), alphaValue))
+        return;
+    if (!isUndefinedOrNull(alphaValue) && !alphaValue->IsBoolean()) {
+        exceptionState.throwTypeError("The 'alpha' property on the class is not a boolean.");
+        return;
+    }
+    bool hasAlphaChannel = alphaValue->IsBoolean() && v8::Local<v8::Boolean>::Cast(alphaValue)->Value();

[haraken, 2016/06/22 00:59:47]

Drive-by: 'alphaValue->IsBoolean() &&' won't be needed.

[Gleb Lanbin, 2016/06/22 04:27:46]

Done. thanks.

+
     v8::Local<v8::Value> prototypeValue;
     if (!v8Call(constructor->Get(context, v8String(isolate, "prototype")), prototypeValue))
         return;
 
     if (isUndefinedOrNull(prototypeValue)) {
         exceptionState.throwTypeError("The 'prototype' object on the class does not exist.");
         return;
     }
 
     if (!prototypeValue->IsObject()) {
@@ skipping 12 matching lines @@
         return;
     }
 
     if (!paintValue->IsFunction()) {
         exceptionState.throwTypeError("The 'paint' property on the prototype is not a function.");
         return;
     }
 
     v8::Local<v8::Function> paint = v8::Local<v8::Function>::Cast(paintValue);
 
-    CSSPaintDefinition* definition = CSSPaintDefinition::create(scriptController()->getScriptState(), constructor, paint, nativeInvalidationProperties, customInvalidationProperties);
+    CSSPaintDefinition* definition = CSSPaintDefinition::create(scriptController()->getScriptState(), constructor, paint, nativeInvalidationProperties, customInvalidationProperties, hasAlphaChannel);
     m_paintDefinitions.set(name, definition);
 
     // Set the definition on any pending generators.
     GeneratorHashSet* set = m_pendingGenerators.get(name);
     if (set) {
         for (const auto& generator : *set) {
             if (generator) {
                 generator->setDefinition(definition);
             }
         }
@@ skipping 15 matching lines @@
 }
 
 DEFINE_TRACE(PaintWorkletGlobalScope)
 {
     visitor->trace(m_paintDefinitions);
     visitor->trace(m_pendingGenerators);
     MainThreadWorkletGlobalScope::trace(visitor);
 }
 
 } // namespace blink