Allows client to access auth token from command line specified file.

blimp/docs/running.md

 # Running Blimp
 
 See [build](build.md) for instructions on how to build Blimp.
 
 ## Running the client
 
 There are both Android and Linux clients.  The Android client is the shipping
 client while the Linux client is used for development purposes.
 
 ### Instructing client to connect to specific host
 
 To have the client connect to a custom engine use the `--engine-ip`,
 `--engine-port`, and `--engine-transport` flags. The possible valid
 values for `--engine-transport` are 'tcp' and 'ssl'.
 An example valid endpoint would be
 `--engine-ip=127.0.0.1 --engine-port=1234 --engine-transport=tcp`.
 
 SSL-encrypted connections take an additional flag
 `--engine-cert-path` which specifies a path to a PEM-encoded certificate
 file (e.g. `--engine-cert-path=/path/to/file.pem`.)
 
 ### Requesting the complete page from the engine
 The engine sends partially rendered content to the client. To request the complete
 page from the engine, use the `--download-whole-document` flag on the client.
 
+### Specifying the client auth token file
+The client needs access to a file containing a client auth token. One should
+make sure this file is available by pushing it onto the device before running
+the client. One can do this by running the following command:
+
+```bash
+adb push /path/to/blimp_client_token \
+  /data/data/org.chromium.blimp/blimp_client_token
+```
+
+To have the client use the given client auth token file, use the
+`--blimp-client-token-path` flag (e.g.
+`--blimp-client-token-path=/data/data/org.chromium.blimp/blimp_client_token`)
+
+
 ### Android Client
 
 Install the Blimp APK with the following:
 
 ```bash
 ./build/android/adb_install_apk.py $(PRODUCT_DIR)/apks/Blimp.apk
 ```
 
 Set up any command line flags with:
 
@@ skipping 56 matching lines @@
 * `--blimp-client-token-path=$PATH`: Path to a file containing a nonempty
   token string. If this is not present, the engine will fail to boot.
 * `--use-remote-compositing`: Ensures that the renderer uses the remote
   compositor.
 * `--disable-cached-picture-raster`: Ensures that rasterized content is not
   destroyed before serialization.
 * `--android-fonts-path=$PATH`: Path to where the fonts are located.
   Typically this would be `out-linux/Debug/gen/third_party/blimp_fonts`.
 * `--disable-remote-fonts`: Disables downloading of custom web fonts in the
   renderer.
-
-#### Typical invocation
-When the client connects to a manually specified engine instead of using the
-assigner, it will use a dummy token. The engine needs to know what this token
-is, so it must be provided using the `--blimp-client-token-path` flag. The token
-is available in the constant `kDummyClientToken` in
-`blimp/client/session/assignment_source.h`. You can easily store that to a file
-by running the following command once:
-
-```bash
-awk '{if ( match($0, /^\s*const char kDummyClientToken.*/) ) { print substr($5, 2, length($5)-3);} }' \
-  ./blimp/client/session/assignment_source.h > /tmp/blimpengine-token
-```
-
-Then start the engine using these flags:
-
-```bash
-out-linux/Debug/blimp_engine_app \
-  --android-fonts-path=out-linux/Debug/gen/third_party/blimp_fonts \
-  --blimp-client-token-path=/tmp/blimpengine-token \
-  --enable-logging=stderr \
-  --vmodule="blimp*=1"
-```