[Benchmark] "No backend is available" occurs when testing WebDNN on Android

[Christywl]

Test benchmark with https://github.com/mil-tokyo/webdnn/commit/7befcdae967654e3e9ed37e994be5a99fb62985a, "No backend is available" occurs with Google Chrome Stable 68.0.3440.91 and 69.0.3497.91 on Android:

• WebDNN(WASM backend) + ResNet50
• WebDNN(WASM backend) + Inception V3
• WebDNN(WASM backend + Optimize) + Inception V3

It works fine on Mac.

[milhidaka]

I reproduced the bug on our android tablet. Keras.js's official demo, which does not share any code with webdnn, also don't work. https://transcranial.github.io/keras-js/#/ It seems to be some bug in browser, but I couldn't find the exact problem currently.

[TomatoDroid]

你好，请问问题解决了么