Use texture size to determine precision of texture coord varyings

gyp/gmslides.gypi

 # include this gypi to include all the golden master slides.
 {
   'include_dirs': [
     '../gm',
     # include dirs needed by particular GMs
     '../src/utils/debugger',
     '../src/images',
     '../src/lazy',
   ],
   'conditions': [
@@ skipping 168 matching lines @@
         '../gm/strokerect.cpp',
         '../gm/strokerects.cpp',
         '../gm/strokes.cpp',
         '../gm/stroketext.cpp',
         '../gm/surface.cpp',
         '../gm/tablecolorfilter.cpp',
         '../gm/texteffects.cpp',
         '../gm/testimagefilters.cpp',
         '../gm/texdata.cpp',
         '../gm/variedtext.cpp',
+        '../gm/tallstretchedbitmaps.cpp',
         '../gm/textblob.cpp',
         '../gm/textblobshader.cpp',
         '../gm/texturedomaineffect.cpp',
         '../gm/thinrects.cpp',
         '../gm/thinstrokedrects.cpp',
         '../gm/tiledscaledbitmap.cpp',
         '../gm/tileimagefilter.cpp',
         '../gm/tilemodes.cpp',
         '../gm/tilemodes_scaled.cpp',
         '../gm/tinybitmap.cpp',
@@ skipping 43 matching lines @@
         '../gm/shadertext2.cpp',
         '../gm/shadertext3.cpp',
 
         # TODO(reed): Allocates more memory than Android devices are capable of
         # fulfilling. See http://skbug.com/1978
         '../gm/verylargebitmap.cpp',
       ],
     }],
   ],
 }