Added switch to disable specified GL extensions.

ui/gl/gl_api_unittest.cc

Index: ui/gl/gl_api_unittest.cc
diff --git a/ui/gl/gl_api_unittest.cc b/ui/gl/gl_api_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..44bc224d2b987bddcd3c5b40025398d551577c29
--- /dev/null
+++ b/ui/gl/gl_api_unittest.cc
@@ -0,0 +1,155 @@
+// Copyright 2015 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 "base/command_line.h"
+#include "base/memory/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gl/gl_gl_api_implementation.h"
+#include "ui/gl/gl_implementation.h"
+#include "ui/gl/gl_switches.h"
+
+namespace gfx {
+
+class GLApiTest : public testing::Test {
+ public:
+  void SetUp() override {
+    fake_extension_string_ = "";
+    num_fake_extension_strings_ = 0;
+    fake_extension_strings_ = nullptr;
+
+    driver_.reset(new DriverGL());
+    api_.reset(new RealGLApi());
+
+    driver_->fn.glGetStringFn =
+        reinterpret_cast<glGetStringProc>(&FakeGetString);
+    driver_->fn.glGetStringiFn =
+        reinterpret_cast<glGetStringiProc>(&FakeGetStringi);
+    driver_->fn.glGetIntegervFn =
+        reinterpret_cast<glGetIntegervProc>(&FakeGetIntegervFn);
+  }
+
+  void TearDown() override {
+    api_.reset(nullptr);
+    driver_.reset(nullptr);
+
+    SetGLImplementation(kGLImplementationNone);
+    fake_extension_string_ = "";
+    num_fake_extension_strings_ = 0;
+    fake_extension_strings_ = nullptr;
+  }
+
+  void InitializeAPI(base::CommandLine* command_line) {
+    api_.reset(new RealGLApi());
+    if (command_line)
+      api_->InitializeWithCommandLine(driver_.get(), command_line);
+    else
+      api_->Initialize(driver_.get());
+  }
+
+  void SetFakeExtensionString(const char* fake_string) {
+    SetGLImplementation(kGLImplementationDesktopGL);
+    fake_extension_string_ = fake_string;
+  }
+
+  void SetFakeExtensionStrings(const char** fake_strings, uint32_t count) {
+    SetGLImplementation(kGLImplementationDesktopGLCoreProfile);
+    num_fake_extension_strings_ = count;
+    fake_extension_strings_ = fake_strings;
+  }
+
+  static const GLubyte* FakeGetString(GLenum name) {
+    return reinterpret_cast<const GLubyte*>(fake_extension_string_);
+  }
+
+  static void FakeGetIntegervFn(GLenum pname, GLint* params) {
+    *params = num_fake_extension_strings_;
+  }
+
+  static const GLubyte* FakeGetStringi(GLenum name, GLuint index) {
+    return (index < num_fake_extension_strings_) ?
+           reinterpret_cast<const GLubyte*>(fake_extension_strings_[index]) :
+           nullptr;
+  }
+
+  const char* GetExtensions() {
+    return reinterpret_cast<const char*>(api_->glGetStringFn(GL_EXTENSIONS));
+  }
+
+  uint32_t GetNumExtensions() {
+    GLint num_extensions = 0;
+    api_->glGetIntegervFn(GL_NUM_EXTENSIONS, &num_extensions);
+    return static_cast<uint32_t>(num_extensions);
+  }
+
+  const char* GetExtensioni(uint32_t index) {
+    return reinterpret_cast<const char*>(api_->glGetStringiFn(GL_EXTENSIONS,
+                                                              index));
+  }
+
+ protected:
+  static const char* fake_extension_string_;
+
+  static uint32_t num_fake_extension_strings_;
+  static const char** fake_extension_strings_;
+
+  scoped_ptr<DriverGL> driver_;
+  scoped_ptr<RealGLApi> api_;
+};
+
+const char* GLApiTest::fake_extension_string_ = "";
+
+uint32_t GLApiTest::num_fake_extension_strings_ = 0;
+const char** GLApiTest::fake_extension_strings_ = nullptr;
+
+TEST_F(GLApiTest, DisabledExtensionStringTest) {
+  static const char* kFakeExtensions = "GL_EXT_1 GL_EXT_2 GL_EXT_3 GL_EXT_4";
+  static const char* kFakeDisabledExtensions = "GL_EXT_1,GL_EXT_2,GL_FAKE";
+  static const char* kFilteredExtensions = "GL_EXT_3 GL_EXT_4";
+
+  SetFakeExtensionString(kFakeExtensions);
+  InitializeAPI(nullptr);
+
+  EXPECT_STREQ(kFakeExtensions, GetExtensions());
+
+  base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+  command_line.AppendSwitchASCII(switches::kDisableGLExtensions,
+                                 kFakeDisabledExtensions);
+  InitializeAPI(&command_line);
+
+  EXPECT_STREQ(kFilteredExtensions, GetExtensions());
+}
+
+TEST_F(GLApiTest, DisabledExtensionStringIndexTest) {
+  static const char* kFakeExtensions[] = {
+    "GL_EXT_1",
+    "GL_EXT_2",
+    "GL_EXT_3",
+    "GL_EXT_4"
+  };
+  static const char* kFakeDisabledExtensions = "GL_EXT_1,GL_EXT_2,GL_FAKE";
+  static const char* kFilteredExtensions[] = {
+    "GL_EXT_3",
+    "GL_EXT_4"
+  };
+
+  SetFakeExtensionStrings(kFakeExtensions, arraysize(kFakeExtensions));
+  InitializeAPI(nullptr);
+
+  EXPECT_EQ(arraysize(kFakeExtensions), GetNumExtensions());
+  for (uint32_t i = 0; i < arraysize(kFakeExtensions); ++i) {
+    EXPECT_STREQ(kFakeExtensions[i], GetExtensioni(i));
+  }
+
+  base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+  command_line.AppendSwitchASCII(switches::kDisableGLExtensions,
+                                 kFakeDisabledExtensions);
+  InitializeAPI(&command_line);
+
+  EXPECT_EQ(arraysize(kFilteredExtensions), GetNumExtensions());
+  for (uint32_t i = 0; i < arraysize(kFilteredExtensions); ++i) {
+    EXPECT_STREQ(kFilteredExtensions[i], GetExtensioni(i));
+  }
+}
+
+}  // namespace gpu