Added dummy definition for CanPartialSwap() in VulkanRenderer class

cc/output/vulkan_renderer.cc

Index: cc/output/vulkan_renderer.cc
diff --git a/cc/output/vulkan_renderer.cc b/cc/output/vulkan_renderer.cc
index 5caa02ee100e7951e5d84aef343ef8877adf9e98..7adfe614557f380e8deeab37c374de33b8310f4e 100644
--- a/cc/output/vulkan_renderer.cc
+++ b/cc/output/vulkan_renderer.cc
@@ -17,6 +17,11 @@ void VulkanRenderer::ReceiveSwapBuffersAck(const CompositorFrameAck& ack) {
   NOTIMPLEMENTED();
 }
 
+bool VulkanRenderer::CanPartialSwap() {
+   NOTIMPLEMENTED();
+   return true;
+}
+
 VulkanRenderer::VulkanRenderer(const RendererSettings* settings,
                                OutputSurface* output_surface,
                                ResourceProvider* resource_provider,