Add basic debugging instructions for Android Studio.

docs/android_debugging_instructions.md

 # Android Debugging Instructions
 
 Chrome on Android has java and c/c++ code. Each "side" have its own set of tools
 for debugging. Here's some tips.
 
 [TOC]
 
 ## Setting up command line flags
 
 Various commands below requires setting up command line flags.
@@ skipping 74 matching lines @@
 
 Example:
 
 ```java
 @ViewDebug.ExportedProperty(category="chrome")
 private int mSuperNiftyDrawingProperty;
 ```
 
 ## Debugging Java
 
+### Eclipse
 *   In Eclipse, make a debug configuration of type "Remote Java Application".
     Choose a "Name" and set "Port" to `8700`.
 
 *   Make sure Eclipse Preferences > Run/Debug > Launching > "Build (if required)
     before launching" is unchecked.
 
 *   Run Android Device Monitor:
 
     ```shell
     third_party/android_tools/sdk/tools/monitor
     ```
 
 *   Now select the process you want to debug in Device Monitor (the port column
     should now mention 8700 or xxxx/8700).
 
 *   Run your debug configuration, and switch to the Debug perspective.
 
+### Android Studio
+*   Build and install the desired target
+
+*   Click the "Attach debugger to Android process" (see
+[here](https://developer.android.com/studio/debug/index.html) for more)
+
 ## Waiting for Java Debugger on Early Startup
 
 *   To debug early startup, pass `--wait-for-java-debugger` as a command line
     flag.
 
 ## Debugging C/C++
 
 Under `build/android`, there are a few scripts:
 
 ```shell
@@ skipping 119 matching lines @@
 build/android/adb_gdb --output-directory=out/Default --package-name=org.chromium.native_test
 ```
 
 After attaching gdb to the process you can use it normally. For example:
 
 ```
 (gdb) break main
 Breakpoint 1 at 0x9750793c: main. (2 locations)
 (gdb) continue
 ```