Update from https://crrev.com/303153

cc/output/shader.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/output/shader.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 528 matching lines @@
   matrix_location_ = locations[0];
   quad_location_ = locations[1];
   vertex_tex_transform_location_ = locations[2];
 }
 
 std::string VertexShaderTile::GetShaderString() const {
   // clang-format off
   return VERTEX_SHADER(
       // clang-format on
       attribute TexCoordPrecision vec4 a_position;
+      attribute TexCoordPrecision vec2 a_texCoord;
       attribute float a_index;
       uniform mat4 matrix;
       uniform TexCoordPrecision vec2 quad[4];
       uniform TexCoordPrecision vec4 vertexTexTransform;
       varying TexCoordPrecision vec2 v_texCoord;
       void main() {
         vec2 pos = quad[int(a_index)];  // NOLINT
         gl_Position = matrix * vec4(pos, a_position.z, a_position.w);
-        v_texCoord = pos.xy * vertexTexTransform.zw + vertexTexTransform.xy;
+        v_texCoord = a_texCoord * vertexTexTransform.zw + vertexTexTransform.xy;
       }
       // clang-format off
   );  // NOLINT(whitespace/parens)
   // clang-format on
 }
 
 VertexShaderTileAA::VertexShaderTileAA()
     : matrix_location_(-1),
       viewport_location_(-1),
       quad_location_(-1),
@@ skipping 1411 matching lines @@
         vec2 coord = mod(floor(texCoord * frequency * 2.0), 2.0);
         float picker = abs(coord.x - coord.y);  // NOLINT
         gl_FragColor = mix(color1, color2, picker) * alpha;
       }
       // clang-format off
   );  // NOLINT(whitespace/parens)
   // clang-format on
 }
 
 }  // namespace cc