canvas2d: Handle resource allocation failure in CanvasResourceProvider.

A failure to allocate a CanvasResource should be handled safely.

R=fserb@chromium.org

Bug: 994979
Change-Id: I93303b7874a0286621344f7f9a6cdab9495e0919
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1772303
Auto-Submit: Khushal <khushalsagar@chromium.org>
Commit-Queue: Fernando Serboncini <fserb@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691624}

third_party/blink/renderer/platform/graphics/canvas_resource_provider.cc

@@ -663,7 +663,7 @@ class CanvasResourceProviderSharedImage : public CanvasResourceProvider {
 
   sk_sp<SkSurface> CreateSkSurface() const override {
     TRACE_EVENT0("blink", "CanvasResourceProviderSharedImage::CreateSkSurface");
-    if (IsGpuContextLost())
+    if (IsGpuContextLost() || !resource_)
       return nullptr;
 
     if (is_accelerated_) {