Unit tests have been created for the GPUTiming.

ui/gl/gpu_timing_unittest.cc

Index: ui/gl/gpu_timing_unittest.cc
diff --git a/ui/gl/gpu_timing_unittest.cc b/ui/gl/gpu_timing_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a567ce6363c1740cdafcb2011cad39a8e2817b69
--- /dev/null
+++ b/ui/gl/gpu_timing_unittest.cc
@@ -0,0 +1,81 @@
+// 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/bind.h"
+#include "base/memory/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gl/gl_context_stub_with_extensions.h"
+#include "ui/gl/gl_implementation.h"
+#include "ui/gl/gl_mock.h"
+#include "ui/gl/gl_surface.h"
+#include "ui/gl/gpu_preference.h"
+#include "ui/gl/gpu_timing.h"
+
+namespace gfx {
+
+class GPUTimingTest : public testing::Test {
+ public:
+  void SetUp() override {
+    setup_ = false;
+    fake_cpu_time_ = 0;
+  }
+
+  void TearDown() override {
+    context_ = nullptr;
+  }
+
+  void SetupGLContext(const char* gl_version, const char* gl_extensions) {
+    ASSERT_FALSE(setup_) << "Cannot setup GL context twice.";
+    gfx::SetGLGetProcAddressProc(gfx::MockGLInterface::GetGLProcAddress);
+    gfx::GLSurface::InitializeOneOffWithMockBindingsForTests();
+    gl_.reset(new ::testing::StrictMock< ::gfx::MockGLInterface>());
+    ::gfx::MockGLInterface::SetGLInterface(gl_.get());
+
+    context_ = new gfx::GLContextStubWithExtensions;
+    context_->AddExtensionsString(gl_extensions);
+    context_->SetGLVersionString(gl_version);
+
+    setup_ = true;
+  }
+
+  scoped_refptr<GPUTimingClient> CreateGPUTimingClient() {
+    if (!setup_) {
+      SetupGLContext("2.0", "");
+    }
+    return context_->CreateGPUTimingClient();
+  }
+
+  void SetFakeCPUTime(int64_t fake_cpu_time) {
+    fake_cpu_time_ = fake_cpu_time;
+  }
+
+ protected:
+  static int64_t GetFakeCPUTime() {
+    return fake_cpu_time_;
+  }
+
+ private:
+  static int64_t fake_cpu_time_;
+
+  bool setup_ = false;
+  scoped_ptr< ::testing::StrictMock< ::gfx::MockGLInterface> > gl_;
+  scoped_refptr<gfx::GLContextStubWithExtensions> context_;
+};
+
+int64_t GPUTimingTest::fake_cpu_time_ = 0;
+
+TEST_F(GPUTimingTest, FakeTimerTest) {
+  // Tests that we can properly set fake cpu times.
+  SetFakeCPUTime(123);
+
+  scoped_refptr<GPUTimingClient> gpu_timing_client = CreateGPUTimingClient();
+  gpu_timing_client->SetCpuTimeForTesting(base::Bind(&GetFakeCPUTime));
+  EXPECT_EQ(123, gpu_timing_client->GetCurrentCPUTime());
+
+  base::Callback<int64_t(void)> empty;
+  gpu_timing_client->SetCpuTimeForTesting(empty);
+  EXPECT_NE(123, gpu_timing_client->GetCurrentCPUTime());
+}
+
+}  // namespace gpu