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

Index: gpu/command_buffer/service/gles2_cmd_clear_framebuffer.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_clear_framebuffer.cc b/gpu/command_buffer/service/gles2_cmd_clear_framebuffer.cc
index b0fcd5f61958e38bde5bfcde865ee18c8d8a9735..9e6eccebc4b92bfde846db72d6b00636ff4ed795 100644
--- a/gpu/command_buffer/service/gles2_cmd_clear_framebuffer.cc
+++ b/gpu/command_buffer/service/gles2_cmd_clear_framebuffer.cc
@@ -7,6 +7,7 @@
 #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 {
 
@@ -34,8 +35,16 @@ const char* g_fragment_shader_source = {
   ),
 };
 
-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;
@@ -57,8 +66,13 @@ 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);
 }
 
@@ -82,6 +96,15 @@ void ClearFramebufferResourceManager::Initialize(
                                    -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;
 }
@@ -91,6 +114,10 @@ void ClearFramebufferResourceManager::Destroy() {
     return;
 
   glDeleteProgram(program_);
+  if (vao_ != 0) {
+    glDeleteVertexArraysOES(1, &vao_);
+    vao_ = 0;
+  }
   glDeleteBuffersARB(1, &buffer_id_);
   buffer_id_ = 0;
 }
@@ -113,10 +140,12 @@ void ClearFramebufferResourceManager::ClearFramebuffer(
   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_);
@@ -141,11 +170,15 @@ void ClearFramebufferResourceManager::ClearFramebuffer(
     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,
@@ -180,9 +213,11 @@ void ClearFramebufferResourceManager::ClearFramebuffer(
   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();
 }