Replace ASSERT with DCHECK in core/

third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp

Index: third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp
diff --git a/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp b/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp
index ebd8677aa0f0974de3f7cdf621489e95a648d402..b59a07a1cf8bfedd48e081a3888baff1b8ca7b0d 100644
--- a/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp
+++ b/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp
@@ -78,7 +78,7 @@ void OffscreenCanvas::SetSize(const IntSize& size) {
 }
 
 void OffscreenCanvas::SetNeutered() {
-  ASSERT(!context_);
+  DCHECK(!context_);
   is_neutered_ = true;
   size_.SetWidth(0);
   size_.SetHeight(0);
@@ -209,7 +209,7 @@ void OffscreenCanvas::RegisterRenderingContextFactory(
   CanvasRenderingContext::ContextType type =
       rendering_context_factory->GetContextType();
   ASSERT(type < CanvasRenderingContext::kContextTypeCount);
-  ASSERT(!RenderingContextFactories()[type]);
+  DCHECK(!RenderingContextFactories()[type]);
   RenderingContextFactories()[type] = std::move(rendering_context_factory);
 }