Enable a lot of extensions to increase fuzzer coverage

ui/gl/gl_stub_api.cc

 // Copyright 2016 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 "ui/gl/gl_stub_api.h"
 
 namespace gl {
 
 namespace {
 
 void GenHelper(GLsizei count, GLuint* objects) {
   for (GLsizei i = 0; i < count; ++i)
     objects[i] = i + 1;
 }
 
 }  // anonymous namespace
 
+GLStubApi::GLStubApi()
+    : version_("OpenGL ES 3.0"), extensions_("GL_EXT_framebuffer_object") {}
+
+GLStubApi::~GLStubApi() = default;
+
 GLenum GLStubApi::glCheckFramebufferStatusEXTFn(GLenum target) {
   return GL_FRAMEBUFFER_COMPLETE;
 }
 
 GLuint GLStubApi::glCreateProgramFn(void) {
   return 1;
 }
 
 GLuint GLStubApi::glCreateShaderFn(GLenum type) {
   return 2;
@@ skipping 79 matching lines @@
     case GL_MAX_VERTEX_ATTRIBS:
       *params = 8;
       break;
     case GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS:
       *params = 8;
       break;
     case GL_MAX_TEXTURE_IMAGE_UNITS:
       *params = 8;
       break;
     case GL_MAX_TEXTURE_SIZE:
+    case GL_MAX_RECTANGLE_TEXTURE_SIZE_ARB:
       *params = 2048;
       break;
     case GL_MAX_CUBE_MAP_TEXTURE_SIZE:
       *params = 2048;
       break;
     case GL_MAX_3D_TEXTURE_SIZE:
       *params = 256;
       break;
     case GL_MAX_ARRAY_TEXTURE_LAYERS:
       *params = 256;
@@ skipping 71 matching lines @@
       break;
   }
 }
 
 const GLubyte* GLStubApi::glGetStringFn(GLenum name) {
   switch (name) {
     case GL_RENDERER:
     default:
       return reinterpret_cast<const GLubyte*>("");
     case GL_VERSION:
-      return reinterpret_cast<const GLubyte*>("OpenGL ES 3.0");
+      return reinterpret_cast<const GLubyte*>(version_.c_str());
     case GL_EXTENSIONS:
-      return reinterpret_cast<const GLubyte*>("GL_EXT_framebuffer_object");
+      return reinterpret_cast<const GLubyte*>(extensions_.c_str());
   }
 }
 
 const GLubyte* GLStubApi::glGetStringiFn(GLenum name, GLuint index) {
   return reinterpret_cast<const GLubyte*>("");
 }
 
 GLboolean GLStubApi::glIsBufferFn(GLuint buffer) {
   return GL_TRUE;
 }
@@ skipping 66 matching lines @@
   return GL_TRUE;
 }
 
 GLenum GLStubApi::glWaitSyncFn(GLsync sync,
                                GLbitfield flags,
                                GLuint64 timeout) {
   return GL_TRUE;
 }
 
 }  // namespace gl