Implement dirty bits for Framebuffer.

The dirty bits set the stage for performance improvements in D3D, but
don't actually reduce any of the redundant work just yet.

BUG=angleproject:1260

Change-Id: Ib84e6a9b7aa40c37c41790f492361b22faaf4742
Reviewed-on: https://chromium-review.googlesource.com/318730
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tryjob-Request: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/tests/test_utils/ANGLETest.cpp b/src/tests/test_utils/ANGLETest.cpp
index aebe28c..4fe8fa9 100644
--- a/src/tests/test_utils/ANGLETest.cpp
+++ b/src/tests/test_utils/ANGLETest.cpp
@@ -310,6 +310,11 @@
     mEGLWindow->setDebugEnabled(enabled);
 }
 
+void ANGLETest::setNoErrorEnabled(bool enabled)
+{
+    mEGLWindow->setNoErrorEnabled(enabled);
+}
+
 int ANGLETest::getClientVersion() const
 {
     return mEGLWindow->getClientMajorVersion();