Remove image_decode_tasks_enabled flag.

content/test/fake_compositor_dependencies.h

Index: content/test/fake_compositor_dependencies.h
diff --git a/content/test/fake_compositor_dependencies.h b/content/test/fake_compositor_dependencies.h
index 05e181958f32f9096baafd5871a4e6e539282753..e8d0cdd46aa39a35cce48c8052bdf5263e8bdc63 100644
--- a/content/test/fake_compositor_dependencies.h
+++ b/content/test/fake_compositor_dependencies.h
@@ -35,7 +35,6 @@ class FakeCompositorDependencies : public CompositorDependencies {
   GetCompositorImplThreadTaskRunner() override;
   blink::scheduler::RendererScheduler* GetRendererScheduler() override;
   cc::TaskGraphRunner* GetTaskGraphRunner() override;
-  bool AreImageDecodeTasksEnabled() override;
   bool IsThreadedAnimationEnabled() override;
   bool IsScrollAnimatorEnabled() override;
   bool IsSurfaceSynchronizationEnabled() override;