Submit Compositor Frame from OffscreenCanvas on main

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 b5f8febd6e7bfcd7f93520e4634a53b70aa5fd7f..1d62bf46088754aaa1d7afd728e2f571bcf2cf46 100644
--- a/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp
+++ b/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp
@@ -9,6 +9,7 @@
 #include "core/html/canvas/CanvasRenderingContext.h"
 #include "core/html/canvas/CanvasRenderingContextFactory.h"
 #include "platform/graphics/ImageBuffer.h"
+#include "platform/graphics/OffscreenCanvasFrameDispatcherImpl.h"
 #include "wtf/MathExtras.h"
 #include <memory>
 
@@ -27,11 +28,18 @@ OffscreenCanvas* OffscreenCanvas::create(unsigned width, unsigned height)
 
 void OffscreenCanvas::setWidth(unsigned width)
 {
+    // If this OffscreenCanvas is transferred control by an html canvas,
+    // its size is determined by html canvas's size and cannot be resized.
+    if (m_canvasId >= 0)
+        return;
     m_size.setWidth(clampTo<int>(width));
 }
 
 void OffscreenCanvas::setHeight(unsigned height)
 {
+    // Same comment as above.
+    if (m_canvasId >= 0)
+        return;
     m_size.setHeight(clampTo<int>(height));
 }
 
@@ -134,6 +142,13 @@ bool OffscreenCanvas::isPaintable() const
     return m_context->isPaintable();
 }
 
+OffscreenCanvasFrameDispatcher* OffscreenCanvas::getOrCreateFrameDispatcher()
+{
+    if (!m_frameDispatcher)
+        m_frameDispatcher = wrapUnique(new OffscreenCanvasFrameDispatcherImpl(m_clientId, m_localId, m_nonce, width(), height()));
+    return m_frameDispatcher.get();
+}
+
 DEFINE_TRACE(OffscreenCanvas)
 {
     visitor->trace(m_context);