Don't inherit ANGLETest SetUp and TearDown.

Instead of inheriting from testing::Test's SetUp and TearDown we add
new methods 'testSetUp' and 'testTearDown'. This helps prevent a common
error of forgetting to call the base class method.

Also add a check in the ANGLETest destructor that SetUp and TearDown
have been called.

Bug: angleproject:3393
Change-Id: Iab211305cc06ffea9ca649e864ddc9b180f2cba0
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1593960
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/tests/gl_tests/FramebufferMultiviewTest.cpp b/src/tests/gl_tests/FramebufferMultiviewTest.cpp
index bffa7e5..c2ba006 100644
--- a/src/tests/gl_tests/FramebufferMultiviewTest.cpp
+++ b/src/tests/gl_tests/FramebufferMultiviewTest.cpp
@@ -38,7 +38,7 @@
   protected:
     FramebufferMultiviewLayeredClearTest() : mMultiviewFBO(0), mDepthTex(0), mDepthStencilTex(0) {}
 
-    void TearDown() override
+    void testTearDown() override
     {
         if (mMultiviewFBO != 0)
         {
@@ -67,7 +67,7 @@
             glDeleteTextures(1, &mDepthTex);
             mDepthTex = 0u;
         }
-        MultiviewTest::TearDown();
+        MultiviewTest::testTearDown();
     }
 
     void initializeFBOs(int width,