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

gpu/command_buffer/service/gles2_cmd_decoder.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/gles2_cmd_decoder.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 1648 matching lines @@
   bool DoIsProgram(GLuint client_id);
   bool DoIsRenderbuffer(GLuint client_id);
   bool DoIsShader(GLuint client_id);
   bool DoIsTexture(GLuint client_id);
   bool DoIsSampler(GLuint client_id);
   bool DoIsTransformFeedback(GLuint client_id);
   bool DoIsVertexArrayOES(GLuint client_id);
   bool DoIsPathCHROMIUM(GLuint client_id);
   bool DoIsSync(GLuint client_id);
 
-  void DoLineWidth(GLfloat width);
+  GLfloat DoLineWidth(GLfloat width);
 
   // Wrapper for glLinkProgram
   void DoLinkProgram(GLuint program);
 
   // Wrapper for glReadBuffer
   void DoReadBuffer(GLenum src);
 
   // Wrapper for glRenderbufferStorage.
   void DoRenderbufferStorage(
       GLenum target, GLenum internalformat, GLsizei width, GLsizei height);
@@ skipping 6768 matching lines @@
   GLenum error = LOCAL_PEEK_GL_ERROR("glRenderbufferStorage");
   if (error == GL_NO_ERROR) {
     // TODO(gman): If tetxures tracked which framebuffers they were attached to
     // we could just mark those framebuffers as not complete.
     framebuffer_manager()->IncFramebufferStateChangeCount();
     renderbuffer_manager()->SetInfo(
         renderbuffer, 0, internalformat, width, height);
   }
 }
 
-void GLES2DecoderImpl::DoLineWidth(GLfloat width) {
-  glLineWidth(
-      std::min(std::max(width, line_width_range_[0]), line_width_range_[1]));
+error::Error GLES2DecoderImpl::HandleLineWidth(uint32_t immediate_data_size,
+                                               const volatile void* cmd_data) {
+  const volatile gles2::cmds::LineWidth& c =
+      *static_cast<const volatile gles2::cmds::LineWidth*>(cmd_data);
+  GLfloat width = static_cast<GLfloat>(c.width);
+  if (width <= 0.0f || std::isnan(width)) {
+    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "LineWidth", "width out of range");
+    return error::kNoError;
+  }
+  if (state_.line_width != width) {
+    // Save adjusted line width.
+    state_.line_width = DoLineWidth(width);

[piman, 2016/11/07 19:38:01]

This is incorrect, though, because it means the value returned by
glGetIIntegerv(GL_LINE_WIDTH, ...) will not match the value passed to
glLineWidth any more (it's supposed to).

We either need to keep both the original value and the clamped value, or we need
to do the clamping again in ContextState::InitState

+  }
+  return error::kNoError;
+}
+
+GLfloat GLES2DecoderImpl::DoLineWidth(GLfloat width) {
+  GLfloat real_width =
+      std::min(std::max(width, line_width_range_[0]), line_width_range_[1]);
+  glLineWidth(real_width);
+  return real_width;
 }
 
 void GLES2DecoderImpl::DoLinkProgram(GLuint program_id) {
   TRACE_EVENT0("gpu", "GLES2DecoderImpl::DoLinkProgram");
   SCOPED_UMA_HISTOGRAM_TIMER("GPU.DoLinkProgramTime");
   Program* program = GetProgramInfoNotShader(
       program_id, "glLinkProgram");
   if (!program) {
     return;
   }
@@ skipping 10315 matching lines @@
 }
 
 // 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 "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu