Always use sized internal formats for textures in TextureGL. On desktop GL, using an internal format of GL_RGBA produces GL_RGBA8 textures even if format is set to GL_FLOAT. Use sized internal formats whenever possible to ensure that the internal format of the texture is the expected format. Fixes: * conformance/extensions/oes-texture-float-with-image-data.htm * conformance/extensions/oes-texture-float-with-image.html * conformance/extensions/oes-texture-float.html * conformance/extensions/oes-texture-half-float-linear.html * conformance/extensions/oes-texture-half-float-with-image-data.html * conformance/extensions/oes-texture-half-float-with-image.html * conformance/extensions/oes-texture-half-float.html BUG=angleproject:884 Change-Id: I48f220a4da518fff5831155a45c04cafcdffd33b Reviewed-on: https://chromium-review.googlesource.com/288350 Tested-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>