Fix the DCHECK problem for TextureManager::TextureInfo::SetTarget

It's because GLES2DecoderImpl::HandleDestroyStreamTextureCHROMIUM can
clear the target of a streamtexture which is not zero.
It occurs when destorying a html5 video on Android platform because it will
create/destroy streamtextures.

BUG=
TEST=


Review URL: https://chromiumcodereview.appspot.com/11421148

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@170915 0039d316-1c4b-4281-b951-d872f2087c98

gpu/command_buffer/service/gles2_cmd_decoder.cc

@@ -8742,7 +8742,6 @@ error::Error GLES2DecoderImpl::HandleDestroyStreamTextureCHROMIUM(
 
     stream_texture_manager_->DestroyStreamTexture(info->service_id());
     info->SetStreamTexture(false);
-    texture_manager()->SetInfoTarget(info, 0);
   } else {
     SetGLError(GL_INVALID_VALUE,
                "glDestroyStreamTextureCHROMIUM", "bad texture id.");