Have SetLostContextCallback use RepeatingClosure.

WebGraphicsContext3DProvider::SetLostContextCallback already
exlicitly uses base::RepeatingClosure so converting two overrides
to do the same.

Bug: 1007835
Change-Id: Id83a1067d9c555700b630deb75fe2b3d13c93d0d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1988487Reviewed-by: Miguel Casas <mcasas@chromium.org>
Commit-Queue: Chris Mumford <cmumford@google.com>
Cr-Commit-Position: refs/heads/master@{#728663}

third_party/blink/renderer/platform/graphics/gpu/drawing_buffer_test_helpers.h

@@ -61,7 +61,7 @@ class WebGraphicsContext3DProviderForTests
     return webgl_preferences_;
   }
   viz::GLHelper* GetGLHelper() override { return nullptr; }
-  void SetLostContextCallback(base::Closure) override {}
+  void SetLostContextCallback(base::RepeatingClosure) override {}
   void SetErrorMessageCallback(
       base::RepeatingCallback<void(const char*, int32_t id)>) override {}
   cc::ImageDecodeCache* ImageDecodeCache(SkColorType color_type) override {

third_party/blink/renderer/platform/graphics/test/fake_web_graphics_context_3d_provider.h

@@ -75,7 +75,7 @@ class FakeWebGraphicsContext3DProvider : public WebGraphicsContext3DProvider {
   gpu::webgpu::WebGPUInterface* WebGPUInterface() override { return nullptr; }
 
   bool BindToCurrentThread() override { return false; }
-  void SetLostContextCallback(base::Closure) override {}
+  void SetLostContextCallback(base::RepeatingClosure) override {}
   void SetErrorMessageCallback(
       base::RepeatingCallback<void(const char*, int32_t id)>) override {}
   cc::ImageDecodeCache* ImageDecodeCache(SkColorType color_type) override {