13903 Implement basic text rendering support in CanvasKit backend (cla: yes)

13904 Fix withIn matcher distance function lookup (cla: yes)

13906 Revert “RendererContextSwitch guard flutter’s gl context rework.” (cla: yes)

13907 allow ignoring toString, hashCode, and == in api_conform_test (cla: yes)

13908 Made a way to turn off the OpenGL operations on the IO thread for backgrounded apps (cla: yes)

13909 [web] Implement PathMetrics.length (cla: yes)

13910 Roll buildroot to a985f7f63ac. (cla: yes)

13918 Add virtual destructor to GPUSurfaceSoftwareDelegate. (cla: yes)