Enable a lot of extensions to increase fuzzer coverage

Pretend the underlying context (stub) supports most of the extensions we care
about, to make sure we exercise the code paths that are enabled by those.

Ideally we would test with arbitrary combinations of those, but this is a good
first step to increase coverage.

BUG=None
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2299413003
Cr-Commit-Position: refs/heads/master@{#416369}

gpu/command_buffer/tests/fuzzer_main.cc

@@ -44,6 +44,41 @@ const size_t kTransferBufferSize = 16384;
 const size_t kSmallTransferBufferSize = 16;
 const size_t kTinyTransferBufferSize = 3;
 
+static const char kExtensions[] =
+    "GL_AMD_compressed_ATC_texture "
+    "GL_ANGLE_texture_compression_dxt3 "
+    "GL_ANGLE_texture_compression_dxt5 "
+    "GL_ANGLE_texture_usage "
+    "GL_APPLE_ycbcr_422 "
+    "GL_ARB_texture_rectangle "
+    "GL_EXT_blend_func_extended "
+    "GL_EXT_color_buffer_float "
+    "GL_EXT_disjoint_timer_query "
+    "GL_EXT_draw_buffers "
+    "GL_EXT_frag_depth "
+    "GL_EXT_multisample_compatibility "
+    "GL_EXT_multisampled_render_to_texture "
+    "GL_EXT_occlusion_query_boolean "
+    "GL_EXT_read_format_bgra "
+    "GL_EXT_shader_texture_lod "
+    "GL_EXT_texture_compression_s3tc "
+    "GL_EXT_texture_filter_anisotropic "
+    "GL_IMG_texture_compression_pvrtc "
+    "GL_KHR_blend_equation_advanced "
+    "GL_KHR_blend_equation_advanced_coherent "
+    "GL_KHR_texture_compression_astc_ldr "
+    "GL_NV_EGL_stream_consumer_external "
+    "GL_NV_framebuffer_mixed_samples "
+    "GL_NV_path_rendering "
+    "GL_OES_compressed_ETC1_RGB8_texture "
+    "GL_OES_depth24 "
+    "GL_OES_EGL_image_external "
+    "GL_OES_rgb8_rgba8 "
+    "GL_OES_texture_float "
+    "GL_OES_texture_float_linear "
+    "GL_OES_texture_half_float "
+    "GL_OES_texture_half_float_linear";
+
 class CommandBufferSetup {
  public:
   CommandBufferSetup()
@@ -62,6 +97,9 @@ class CommandBufferSetup {
     gpu_preferences_.enable_unsafe_es3_apis = true;
 
     gl::GLSurfaceTestSupport::InitializeOneOffWithMockBindings();
+
+    api_.set_version("OpenGL ES 3.0");
+    api_.set_extensions(kExtensions);
     gl::SetStubGLApi(&api_);
 
     sync_point_client_ = sync_point_manager_->CreateSyncPointClient(

ui/gl/gl_stub_api.cc

@@ -15,6 +15,11 @@ void GenHelper(GLsizei count, GLuint* objects) {
 
 }  // 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;
 }
@@ -114,6 +119,7 @@ void GLStubApi::glGetIntegervFn(GLenum pname, GLint* params) {
       *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:
@@ -205,9 +211,9 @@ const GLubyte* GLStubApi::glGetStringFn(GLenum name) {
     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());
   }
 }
 

ui/gl/gl_stub_api.h

@@ -5,6 +5,8 @@
 #ifndef UI_GL_GL_STUB_API_H_
 #define UI_GL_GL_STUB_API_H_
 
+#include <string>
+
 #include "ui/gl/gl_export.h"
 #include "ui/gl/gl_stub_api_base.h"
 
@@ -12,6 +14,15 @@ namespace gl {
 
 class GL_EXPORT GLStubApi: public GLStubApiBase {
  public:
+  GLStubApi();
+  ~GLStubApi() override;
+
+  void set_version(std::string version) { version_ = std::move(version); }
+
+  void set_extensions(std::string extensions) {
+    extensions_ = std::move(extensions);
+  }
+
   GLenum glCheckFramebufferStatusEXTFn(GLenum target) override;
   GLuint glCreateProgramFn(void) override;
   GLuint glCreateShaderFn(GLenum type) override;
@@ -54,6 +65,12 @@ class GL_EXPORT GLStubApi: public GLStubApiBase {
   GLenum glWaitSyncFn(GLsync sync,
                       GLbitfield flags,
                       GLuint64 timeout) override;
+
+ private:
+  std::string version_;
+  std::string extensions_;
+
+  DISALLOW_COPY_AND_ASSIGN(GLStubApi);
 };
 
 }  // namespace gl