Capture/Replay: Fix capture-enabled libs build. Adds a build option to use the capture libraries in the default output location for libGLESv2. With |angle_with_capture_by_default| enabled, libGLESv2 will have capture enabled and the non-capture libGLESv2 is built as libGLESv2_no_capture. Also moves the FrameCapture to be owned by gl::Context. Rearranges the code a bit so that we don't require a separate version of libANGLE for capture. Also implements a read pixels entry point parameter. Bug: angleproject:3611 Change-Id: Ic528e43e4779f794c8b6d0bf35410166dacc81b1 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1719064 Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>