Cleanup: Remove unused variables in chrome/ found by Scythe.

chrome/renderer/chrome_render_process_observer.cc

Index: chrome/renderer/chrome_render_process_observer.cc
diff --git a/chrome/renderer/chrome_render_process_observer.cc b/chrome/renderer/chrome_render_process_observer.cc
index c1c97c6dc8eb5abc7fe8112c89a8d1e509daf1e8..866934cfbf2a45d6642cb0fccb1da015a6002165 100644
--- a/chrome/renderer/chrome_render_process_observer.cc
+++ b/chrome/renderer/chrome_render_process_observer.cc
@@ -208,10 +208,8 @@ void HeapStatisticsCollector::SendStatsToBrowser(int round_id) {
 
 bool ChromeRenderProcessObserver::is_incognito_process_ = false;
 
-ChromeRenderProcessObserver::ChromeRenderProcessObserver(
-    ChromeContentRendererClient* client)
-    : client_(client),
-      webkit_initialized_(false) {
+ChromeRenderProcessObserver::ChromeRenderProcessObserver()
+    : webkit_initialized_(false) {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();