Reland Fixed compiler warning C4267 'conversion from 'size_t' to 'type', possible loss of data'
Additional warnings found with more testing and added C4267 warning disable only for angle_libpng

BUG=angleproject:1120

Change-Id: Ic403dcff5a8018056fa51a8c408e64207f3362eb
Reviewed-on: https://chromium-review.googlesource.com/293028
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/tests/gl_tests/CubeMapTextureTest.cpp b/src/tests/gl_tests/CubeMapTextureTest.cpp
index aec09a9..7d99f7c 100644
--- a/src/tests/gl_tests/CubeMapTextureTest.cpp
+++ b/src/tests/gl_tests/CubeMapTextureTest.cpp
@@ -98,7 +98,7 @@
     glBindFramebuffer(GL_FRAMEBUFFER, fbo);
     EXPECT_GL_NO_ERROR();
 
-    for (size_t face = 0; face < 6; face++)
+    for (GLenum face = 0; face < 6; face++)
     {
         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, tex, 0);
         EXPECT_GL_NO_ERROR();
@@ -112,7 +112,7 @@
         EXPECT_GL_NO_ERROR();
     }
 
-    for (size_t face = 0; face < 6; face++)
+    for (GLenum face = 0; face < 6; face++)
     {
         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, tex, 0);
         EXPECT_GL_NO_ERROR();