fix --show-composited-layer-borders on Mac

gpu/command_buffer/service/context_state.cc

 // Copyright (c) 2012 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 "gpu/command_buffer/service/context_state.h"
 
 #include <stddef.h>
 
 #include <cmath>
 
@@ skipping 212 matching lines @@
       fbo_binding_for_scissor_workaround_dirty(false),
       framebuffer_srgb_(false),
       feature_info_(feature_info),
       error_state_(ErrorState::Create(error_state_client, logger)) {
   Initialize();
 }
 
 ContextState::~ContextState() {
 }
 
+void ContextState::SetLineWidthBounds(GLfloat min, GLfloat max) {
+  line_width_min_ = min;
+  line_width_max_ = max;
+}
+
 void ContextState::RestoreTextureUnitBindings(
     GLuint unit, const ContextState* prev_state) const {
   DCHECK_LT(unit, texture_units.size());
   const TextureUnit& texture_unit = texture_units[unit];
   GLuint service_id_2d = Get2dServiceId(texture_unit);
   GLuint service_id_cube = GetCubeServiceId(texture_unit);
   GLuint service_id_oes = GetOesServiceId(texture_unit);
   GLuint service_id_arb = GetArbServiceId(texture_unit);
 
   bool bind_texture_2d = true;
@@ skipping 47 matching lines @@
 void ContextState::RestoreUnpackState() const {
   glPixelStorei(GL_UNPACK_ALIGNMENT, unpack_alignment);
   if (bound_pixel_unpack_buffer.get()) {
     glBindBuffer(GL_PIXEL_UNPACK_BUFFER,
                  GetBufferId(bound_pixel_unpack_buffer.get()));
     glPixelStorei(GL_UNPACK_ROW_LENGTH, unpack_row_length);
     glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, unpack_image_height);
   }
 }
 
+void ContextState::DoLineWidth(GLfloat width) const {
+  glLineWidth(
+      std::min(std::max(width, line_width_min_), line_width_max_));
+}
+
 void ContextState::RestoreBufferBindings() const {
   if (vertex_attrib_manager.get()) {
     Buffer* element_array_buffer =
         vertex_attrib_manager->element_array_buffer();
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, GetBufferId(element_array_buffer));
   }
   glBindBuffer(GL_ARRAY_BUFFER, GetBufferId(bound_array_buffer.get()));
   if (feature_info_->IsES3Capable()) {
     glBindBuffer(GL_COPY_READ_BUFFER,
                  GetBufferId(bound_copy_read_buffer.get()));
@@ skipping 400 matching lines @@
   UpdateUnpackParameters();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/service/context_state_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu