[polymer] Merge of master into polymer10-migration

netlog_viewer/README.md

+A standalone WebApp for viewing chrome://net-export
+[NetLog](https://www.chromium.org/developers/design-documents/network-stack/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 full design doc can be found
+[here](https://docs.google.com/document/d/1Ll7T5cguj5m2DqkUTad5DWRCqtbQ3L1q9FRvTN5-Y28/edit#).
+
+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](https://bugs.chromium.org/p/chromium/issues/detail?id=472706)
+
+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).