net-export NetLog dump files

Introduction

This is a WebApp that allows someone to perform post-mortem analysis of a saved NetLog dump. The initial code was taken out of Chromium. The code should contain all changes made to net-internals up to chromium commit 8491b5b9060b61c2b06f51bb5dfcc8098c0cbad1. The full design doc can be found here.

Motivation

There are a few problems with the current system of logging network events within Chromium (see chrome://net-internals) that motivated the design and creation of this new project:

Attempting to add new and improved functionalities to network logging within Chromium comes at the cost of bloating the Chromium binaries.
The renderer process behind chrome://net-internals is privileged meaning it can ask the browser process to do more--monitoring networking events in this case. Generally, privileged UI on Chrome should be minmially complex and small in size, but a large chunk of chrome://net-internals is neither leaving behind a rather large attack surface.
The lack of chrome://net-export on desktop as outlined in an issue

Workflow

To use this WebApp effectively, the first step is having a NetLog dump to use. To export a NetLog dump you can capture events and load them into a file using chrome://net-internals/#export (soon to be chrome://net-export).

Once you have a log file you can use this WebApp to load it for analysis. To do that you need to first git clone into the catapult repository:

git clone https://github.com/catapult-project/catapult.git

Then go to the directory that contains this WebApp by using the cd command:

cd path_to_catapult/catapult/netlog_viewer

Serve the files from an HTTP localhost server with:

python -m SimpleHTTPServer 8080

Visit http://localhost:8080/index.html in your web browser to view the netlog viewer. You will be able to click “Choose File” which will allow you to select the file you exported earlier. From there your NetLog dump will appear as a table filled with all the dump's information. Visit the other tabs to view additional information! There are seven tabs that are currently fully functional (Import, Events, Proxy, Timeline, DNS, Sockets, Cache).