Added command line switches and UI (controlled via a build option)

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 6044b5276044f314d6536c7861b052edb6dbdfe1..a7ec53e1e4b8d8919ea3369f6a8e6c5c86f3ad14 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -279,6 +279,10 @@
     'clang_load%': '',
     'clang_add_plugin%': '',
 
+    # Enable sampling based profiler.
+    # See http://google-perftools.googlecode.com/svn/trunk/doc/cpuprofile.html
+    'profiling%': '0',
+
     # Override whether we should use Breakpad on Linux. I.e. for Chrome bot.
     'linux_breakpad%': 0,
     # And if we want to dump symbols for Breakpad-enabled builds.
@@ -536,6 +540,9 @@
       ['touchui==1', {
         'defines': ['TOUCH_UI=1'],
       }],
+      ['profiling==1', {
+        'defines': ['ENABLE_PROFILING=1'],
+      }],
       ['remoting==1', {
         'defines': ['ENABLE_REMOTING=1'],
       }],
@@ -1014,6 +1021,12 @@
                   '-fno-ident',
                 ],
               }],
+              ['profiling==1', {
+                'cflags': [
+                  '-fno-omit-frame-pointer',
+                  '-g',
+                ],
+              }],
             ]
           },
         },