iPad - iframe can lose grass

[phet-steele]

@aadish I'm absolutely willing to bet this is device specific and will not need to be fixed since I only see this on Tycho. This issue can happen multiple ways; some easy ways to reproduce:

1. Go to the weights pool.
2. Change units around between Atmospheres, English, and Metric (sometimes you don't even need to do this step!).

or

1. Go to the trapezoid pool.
2. Add water.

Tested on iPad 2 iOS 9.3.2 (Tycho). For phetsims/tasks/issues/585.

[phet-steele]

Troubleshooting information: Name: ‪Under Pressure‬ URL: http://www.colorado.edu/physics/phet/dev/html/under-pressure/1.1.0-dev.5/under-pressure_en.html Version: 1.1.0-dev.5 2016-04-29 20:29:02 UTC Features missing: fullscreen User Agent: Mozilla/5.0 (iPad; CPU OS 9_3_2 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13F51a Safari/601.1 Language: en-us Window: 1024x671 Pixel Ratio: 1/1 WebGL: WebGL 1.0 (OpenGL ES 2.0 IMGSGX543-124.1) GLSL: WebGL GLSL ES 1.0 (OpenGL ES GLSL ES 1.00) Vendor: WebKit (WebKit WebGL) Vertex: attribs: 16 varying: 8 uniform: 128 Texture: size: 4096 imageUnits: 8 (vertex: 8, combined: 8) Max viewport: 4096x4096 OES_texture_float: true Dependencies JSON: {"assert":{"sha":"7d27130a","branch":"master"},"axon":{"sha":"5e33541f","branch":"master"},"babel":{"sha":"14af4cf0","branch":"master"},"brand":{"sha":"bb1cfcc6","branch":"master"},"chipper":{"sha":"64ea5afc","branch":"master"},"dot":{"sha":"bf6f038b","branch":"master"},"fluid-pressure-and-flow":{"sha":"2f627795","branch":"master"},"joist":{"sha":"4e95673d","branch":"master"},"kite":{"sha":"dce9765e","branch":"master"},"phet-core":{"sha":"c48bf320","branch":"master"},"phetcommon":{"sha":"eab7fb7f","branch":"master"},"scenery":{"sha":"c2e3040d","branch":"master"},"scenery-phet":{"sha":"436bf61d","branch":"master"},"sherpa":{"sha":"ab4d5c14","branch":"master"},"sun":{"sha":"a69443fc","branch":"master"},"tandem":{"sha":"0ad35fb7","branch":"master"},"under-pressure":{"sha":"d623ba2c","branch":"master"}}

[phet-steele]

:+1: