Implement "Copy image" for canvas (blink side).

Source/core/editing/Editor.cpp

Index: Source/core/editing/Editor.cpp
diff --git a/Source/core/editing/Editor.cpp b/Source/core/editing/Editor.cpp
index a91f9e264bb4617b32adb3b991b1cf02e02eb208..ae29f6e56d910bdbf2bd2bc50de903e15d535369 100644
--- a/Source/core/editing/Editor.cpp
+++ b/Source/core/editing/Editor.cpp
@@ -68,6 +68,7 @@
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
+#include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLTextAreaElement.h"
@@ -426,14 +427,22 @@ static void writeImageNodeToPasteboard(Pasteboard* pasteboard, Node* node, const
     ASSERT(pasteboard);
     ASSERT(node);
 
-    if (!(node->renderer() && node->renderer()->isImage()))
+    RenderObject* renderer = node->renderer();
+    if (!renderer)
         return;
 
-    RenderImage* renderer = toRenderImage(node->renderer());
-    ImageResource* cachedImage = renderer->cachedImage();
-    if (!cachedImage || cachedImage->errorOccurred())
+    Image* image = 0;
+    if (renderer->isImage()) {
+        RenderImage* renderImage = toRenderImage(renderer);
+        ImageResource* cachedImage = renderImage->cachedImage();
+        if (!cachedImage || cachedImage->errorOccurred())
+            return;
+        image = cachedImage->imageForRenderer(renderImage);
+    } else if (renderer->isCanvas()) {
+        image = toHTMLCanvasElement(node)->copiedImage();
+    } else {
         return;
-    Image* image = cachedImage->imageForRenderer(renderer);
+    }
     ASSERT(image);
 
     // FIXME: This should probably be reconciled with HitTestResult::absoluteImageURL.
@@ -444,6 +453,8 @@ static void writeImageNodeToPasteboard(Pasteboard* pasteboard, Node* node, const
         urlString = toElement(node)->getAttribute(XLinkNames::hrefAttr);
     else if (isHTMLEmbedElement(*node) || isHTMLObjectElement(*node))
         urlString = toElement(node)->imageSourceURL();
+    else if (isHTMLCanvasElement(*node))
+        urlString = AtomicString("data:image/png");

[Justin Novosad, 2014/05/09 19:56:38]

This URL does not seem useful. Why not leave urlString empty?

     KURL url = urlString.isEmpty() ? KURL() : node->document().completeURL(stripLeadingAndTrailingHTMLSpaces(urlString));
 
     pasteboard->writeImage(image, url, title);