WIP: Migrate Wiki content over to src/docs

docs/graphical_debugging_aid_chromium_views.md

Index: docs/graphical_debugging_aid_chromium_views.md
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+# Introduction
+
+A simple debugging tool exists to help visualize the views tree during debugging. It consists of 4 components:
+
+  1. The function `View::PrintViewGraph()` (already in the file **view.cc** if you've sync'd recently),
+  1. a gdb script file **viewg.gdb**  (see below),
+  1. the graphViz package (http://www.graphviz.org/ - downloadable for Linux, Windows and Mac), and
+  1. an SVG viewer (_e.g._ Chrome).
+
+# Details
+
+To use the tool,
+
+  1. Make sure you have 'dot' installed (part of graphViz),
+  1. define `TOUCH_DEBUG` and compile chrome with Views enabled,
+  1. run gdb on your build and
+  1. source **viewg.gdb** (this can be done automatically in **.gdbinit**),
+  1. stop at any breakpoint inside class `View` (or any derived class), and
+  1. type `viewg` at the gdb prompt.
+
+This will cause the current view, and any descendants, to be described in a graph which is stored as **~/state.svg** (Windows users may need to modify the script slightly to run under CygWin). If **state.svg** is kept open in a browser window and refreshed each time `viewg` is run, then it provides a graphical representation of the state of the views hierarchy that is always up to date.
+
+It is easy to modify the gdb script to generate PDF in case viewing with evince (or other PDF viewer) is preferred.
+
+If you don't use gdb, you may be able to adapt the script to work with your favorite debugger. The gdb script invokes
+```
+  this->PrintViewGraph(true)
+```
+on the current object, returning `std::string`, whose contents must then be saved to a file in order to be processed by dot.
+
+# viewg.gdb
+
+```
+define viewg
+  if $argc != 0
+    echo Usage: viewg
+  else
+    set pagination off
+    set print elements 0
+    set logging off
+    set logging file ~/state.dot
+    set logging overwrite on
+    set logging redirect on
+    set logging on
+    printf "%s\n", this->PrintViewGraph(true).c_str()
+    set logging off
+    shell dot -Tsvg -o ~/state.svg ~/state.dot
+    set pagination on
+  end
+end
+```