Adjust offset for non-AA line drawing

bug:8114304

The original .375 was chosen to make GL_LINES align with Skia drawing.
The new value of .065 is chosen to be as small as possible to make
triangle-based lines align with Skia, while keeping lines drawn on
integer coordinates unambiguous as to which column/row they draw on.

Also adds more lines in CanvasCompare test to highlight the difference

Change-Id: If578684f2db320682219c3caa625cf79bc62d88f
2 files changed