Support glCopyTexImage2D for float formats.

Bug chromium:853424

Change-Id: I9b2de054baf6b042bcd04c5d023099a39ca20d2a
Reviewed-on: https://swiftshader-review.googlesource.com/19569
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/OpenGL/libGLESv2/libGLESv2.cpp

diff --git a/src/OpenGL/libGLESv2/libGLESv2.cpp b/src/OpenGL/libGLESv2/libGLESv2.cpp
index b6d4718..7ae8126 100644
--- a/src/OpenGL/libGLESv2/libGLESv2.cpp
+++ b/src/OpenGL/libGLESv2/libGLESv2.cpp
@@ -953,6 +953,10 @@
 			{
 				internalformat = gl::GetSizedInternalFormat(internalformat, GL_HALF_FLOAT_OES);
 			}
+			else if(GetColorComponentType(colorbufferFormat) == GL_FLOAT && GetRedSize(colorbufferFormat) == 32)   // GL_EXT_color_buffer_float
+			{
+				internalformat = gl::GetSizedInternalFormat(internalformat, GL_FLOAT);
+			}
 			else
 			{
 				UNIMPLEMENTED();
@@ -6350,6 +6354,7 @@
 		FUNCTION(glDeleteVertexArrays),
 		FUNCTION(glDeleteVertexArraysOES),
 		FUNCTION(glDepthFunc),
+		//FUNCTION(DepthFunc),
 		FUNCTION(glDepthMask),
 		FUNCTION(glDepthRangef),
 		FUNCTION(glDetachShader),