Allow GrReducedClip to take non-integer query bounds

src/gpu/gl/GrGLIRect.h

Index: src/gpu/gl/GrGLIRect.h
diff --git a/src/gpu/gl/GrGLIRect.h b/src/gpu/gl/GrGLIRect.h
index 44f5280fd69fe370729b7720a382b605dc802356..41ac13b753eecfc996d9110f4c90969593836989 100644
--- a/src/gpu/gl/GrGLIRect.h
+++ b/src/gpu/gl/GrGLIRect.h
@@ -54,9 +54,7 @@ struct GrGLIRect {
         }
         fHeight = height;
 
-        SkASSERT(fLeft >= 0);
         SkASSERT(fWidth >= 0);
-        SkASSERT(fBottom >= 0);

[csmartdalton, 2016/07/19 15:59:01]

This started asserting because we aren’t always clamping the scissor down to
draw bounds anymore. A scissor with negative origin is perfectly valid, so
unless there's something else that relies on this assert I think we should just
remove it. (As it was, it asserted if the rect crossed the bottom or left RT
boundaries but not the top or right.)

         SkASSERT(fHeight >= 0);
     }