EGLWindow: remove the unused width and height

EGLWindow does nothing with it per se, but some code was relying on it
to store it. Add width and height to ANGLETest and SampleApplication
instead. Also fix a typo in PerfTestParams, widowWidth -> windowWidth.

BUG=angleproject:1105

Change-Id: I26da607a2e6342864b508a50ee3cf8944608f868
Reviewed-on: https://chromium-review.googlesource.com/287379
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/samples/sample_util/SampleApplication.h b/samples/sample_util/SampleApplication.h
index 3acfb59..74a8701 100644
--- a/samples/sample_util/SampleApplication.h
+++ b/samples/sample_util/SampleApplication.h
@@ -48,6 +48,8 @@
 
   private:
     std::string mName;
+    size_t mWidth;
+    size_t mHeight;
     bool mRunning;
 
     std::unique_ptr<Timer> mTimer;