Test: manual testing in skiavk mode Change-Id: I2fab80bae2787bfdacbc70d0402e98450e59406d
Implement Skia pipelines for OpenGL and Vulkan: base SkiaPipeline, SkiaOpenGLPipeline and SkiaVulkanPipeline. Write unit tests for SkiaPipeline. Test: Built and run manually on angler-eng. Change-Id: Ie02583426cb3547541ad9bf91700602a6163ff58