Make gl_clear_broken workaround support core profile and use it under AMD Linux Catalyst driver

gpu/command_buffer/service/gles2_cmd_clear_framebuffer.cc

 // Copyright 2014 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_clear_framebuffer.h"
 
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "ui/gfx/geometry/size.h"
+#include "ui/gl/gl_version_info.h"
 
 namespace {
 
 #define SHADER(src)            \
   "#ifdef GL_ES\n"             \
   "precision mediump float;\n" \
   "#endif\n" #src
 
 const char* g_vertex_shader_source = {
   SHADER(
     uniform float u_clear_depth;
     attribute vec4 a_position;
     void main(void) {
       gl_Position = vec4(a_position.x, a_position.y, u_clear_depth, 1.0);
     }
   ),
 };
 
 const char* g_fragment_shader_source = {
   SHADER(
     uniform vec4 u_clear_color;
     void main(void) {
       gl_FragColor = u_clear_color;
     }
   ),
 };
 
-void CompileShader(GLuint shader, const char* shader_source) {
-  glShaderSource(shader, 1, &shader_source, 0);
+void CompileShader(GLuint shader,
+                   const char* shader_source,
+                   bool is_desktop_core_profile) {
+  if (is_desktop_core_profile) {
+    const char* version = "#version 150\n";
+    const char* shader_sources[2] = {version, shader_source};
+    glShaderSource(shader, 2, shader_sources, 0);
+  } else {
+    glShaderSource(shader, 1, &shader_source, 0);
+  }
   glCompileShader(shader);
 #if DCHECK_IS_ON()
   GLint compile_status = GL_FALSE;
   glGetShaderiv(shader, GL_COMPILE_STATUS, &compile_status);
   if (GL_TRUE != compile_status) {
     char buffer[1024];
     GLsizei length = 0;
     glGetShaderInfoLog(shader, sizeof(buffer), &length, buffer);
     std::string log(buffer, length);
     DLOG(ERROR) << "Error compiling shader: " << log;
     DLOG(ERROR) << "Shader compilation failure.";
   }
 #endif
 }
 
 }  // namespace
 
 namespace gpu {
 namespace gles2 {
 
 ClearFramebufferResourceManager::ClearFramebufferResourceManager(
-    const gles2::GLES2Decoder* decoder)
-    : initialized_(false), program_(0u), buffer_id_(0u) {
+    const gles2::GLES2Decoder* decoder,
+    const gl::GLVersionInfo& gl_version_info)
+    : initialized_(false),
+      is_desktop_core_profile_(gl_version_info.is_desktop_core_profile),
+      program_(0u),
+      vao_(0),

[Zhenyao Mo, 2017/03/23 17:11:40]

nit: 0u to be consistent with above and below

+      buffer_id_(0u) {
   Initialize(decoder);
 }
 
 ClearFramebufferResourceManager::~ClearFramebufferResourceManager() {
   Destroy();
   DCHECK(!buffer_id_);
 }
 
 void ClearFramebufferResourceManager::Initialize(
     const gles2::GLES2Decoder* decoder) {
   static_assert(
       kVertexPositionAttrib == 0u,
       "kVertexPositionAttrib must be 0");
   DCHECK(!buffer_id_);
 
   glGenBuffersARB(1, &buffer_id_);
   glBindBuffer(GL_ARRAY_BUFFER, buffer_id_);
   const GLfloat kQuadVertices[] = {-1.0f, -1.0f,
                                     1.0f, -1.0f,
                                     1.0f,  1.0f,
                                    -1.0f,  1.0f};
   glBufferData(
       GL_ARRAY_BUFFER, sizeof(kQuadVertices), kQuadVertices, GL_STATIC_DRAW);
+
+  if (is_desktop_core_profile_) {
+    glGenVertexArraysOES(1, &vao_);
+    glBindVertexArrayOES(vao_);
+    glEnableVertexAttribArray(kVertexPositionAttrib);
+    glVertexAttribPointer(kVertexPositionAttrib, 2, GL_FLOAT, GL_FALSE, 0, 0);
+    decoder->RestoreAllAttributes();
+  }
+
   decoder->RestoreBufferBindings();
   initialized_ = true;
 }
 
 void ClearFramebufferResourceManager::Destroy() {
   if (!initialized_)
     return;
 
   glDeleteProgram(program_);
+  if (vao_ != 0) {
+    glDeleteVertexArraysOES(1, &vao_);
+    vao_ = 0;
+  }
   glDeleteBuffersARB(1, &buffer_id_);
   buffer_id_ = 0;
 }
 
 void ClearFramebufferResourceManager::ClearFramebuffer(
     const gles2::GLES2Decoder* decoder,
     const gfx::Size& framebuffer_size,
     GLbitfield mask,
     GLfloat clear_color_red,
     GLfloat clear_color_green,
     GLfloat clear_color_blue,
     GLfloat clear_color_alpha,
     GLfloat clear_depth_value,
     GLint clear_stencil_value) {
   if (!initialized_) {
     DLOG(ERROR) << "Uninitialized manager.";
     return;
   }
 
   if (!program_) {
     program_ = glCreateProgram();
     GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER);
-    CompileShader(vertex_shader, g_vertex_shader_source);
+    CompileShader(vertex_shader, g_vertex_shader_source,
+                  is_desktop_core_profile_);
     glAttachShader(program_, vertex_shader);
     GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
-    CompileShader(fragment_shader, g_fragment_shader_source);
+    CompileShader(fragment_shader, g_fragment_shader_source,
+                  is_desktop_core_profile_);
     glAttachShader(program_, fragment_shader);
     glBindAttribLocation(program_, kVertexPositionAttrib, "a_position");
     glLinkProgram(program_);
 #if DCHECK_IS_ON()
     GLint linked = GL_FALSE;
     glGetProgramiv(program_, GL_LINK_STATUS, &linked);
     if (GL_TRUE != linked)
       DLOG(ERROR) << "Program link failure.";
 #endif
     depth_handle_ = glGetUniformLocation(program_, "u_clear_depth");
     color_handle_ = glGetUniformLocation(program_, "u_clear_color");
     glDeleteShader(fragment_shader);
     glDeleteShader(vertex_shader);
   }
   glUseProgram(program_);
 
 #if DCHECK_IS_ON()
   glValidateProgram(program_);
   GLint validation_status = GL_FALSE;
   glGetProgramiv(program_, GL_VALIDATE_STATUS, &validation_status);
   if (GL_TRUE != validation_status)
     DLOG(ERROR) << "Invalid shader.";
 #endif
 
-  decoder->ClearAllAttributes();
-  glEnableVertexAttribArray(kVertexPositionAttrib);
+  if (vao_) {
+    glBindVertexArrayOES(vao_);
+  } else {
+    decoder->ClearAllAttributes();
+    glEnableVertexAttribArray(kVertexPositionAttrib);
 
-  glBindBuffer(GL_ARRAY_BUFFER, buffer_id_);
-  glVertexAttribPointer(kVertexPositionAttrib, 2, GL_FLOAT, GL_FALSE, 0, 0);
+    glBindBuffer(GL_ARRAY_BUFFER, buffer_id_);
+    glVertexAttribPointer(kVertexPositionAttrib, 2, GL_FLOAT, GL_FALSE, 0, 0);
+  }
 
   glUniform1f(depth_handle_, clear_depth_value);
   glUniform4f(color_handle_, clear_color_red, clear_color_green,
               clear_color_blue, clear_color_alpha);
 
   if (!(mask & GL_COLOR_BUFFER_BIT)) {
     glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
   }
 
   if (mask & GL_DEPTH_BUFFER_BIT) {
@@ skipping 14 matching lines @@
     glStencilMask(0);
   }
 
   glDisable(GL_CULL_FACE);
   glDisable(GL_BLEND);
   glDisable(GL_POLYGON_OFFSET_FILL);
 
   glViewport(0, 0, framebuffer_size.width(), framebuffer_size.height());
   glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
 
+  if (vao_ == 0) {
+    decoder->RestoreBufferBindings();
+  }
   decoder->RestoreAllAttributes();
   decoder->RestoreProgramBindings();
-  decoder->RestoreBufferBindings();
   decoder->RestoreGlobalState();
 }
 
 }  // namespace gles2
 }  // namespace gpu