gpu: glCopyTextureCHROMIUM() checks dest internal format incorrectly.

|internal_format| which a client passes as argument and dest internal format
which is the format of current destination texture can be different. If
different, glCopyTextureCHROMIUM redefines the destination texture. So we
should check dest internal format using |internal_format| argument.

In addition, some platforms reports error when |internal_format| is GL_ALPHA,
GL_LUMINANCE or GL_LUMINANCE_ALPHA, because those formats can not attached as
color attachment of FBO on some platforms. So we restrict |internal_format| to
GL_RGB and GL_RGBA.

TEST=GLCopyTextureCHROMIUMTest.InternalFormat,
     GLCopyTextureCHROMIUMTest.RedefineDestinationTexture

Review URL: https://codereview.chromium.org/481913005

git-svn-id: http://src.chromium.org/svn/trunk/src/gpu@291528 4ff67af0-8c30-449e-8e8b-ad334ec8d88c