Destroy web contents when window is closed.

Previously this was reverted because of Chromium's spammy error
loggings, but it also causes the renderer process not to exit when the
page has been closed. After fixing the spammy error logging, we can now
bring this back.

Fixes atom/atom#3141.

atom/browser/native_window.cc

@@ -449,6 +449,9 @@ void NativeWindow::MoveContents(content::WebContents* source,
 }
 
 void NativeWindow::CloseContents(content::WebContents* source) {
+  // Destroy the WebContents before we close the window.
+  DestroyWebContents();
+
   // When the web contents is gone, close the window immediately, but the
   // memory will not be freed until you call delete.
   // In this way, it would be safe to manage windows via smart pointers. If you

atom/browser/native_window_mac.mm

@@ -241,7 +241,6 @@ void NativeWindowMac::Close() {
 
 void NativeWindowMac::CloseImmediately() {
   [window_ close];
-  window_.reset();
 }
 
 void NativeWindowMac::Move(const gfx::Rect& pos) {

script/lib/config.py

@@ -5,7 +5,7 @@ import sys
 
 NODE_VERSION = 'v0.11.13'
 BASE_URL = 'https://gh-contractor-zcbenz.s3.amazonaws.com/libchromiumcontent'
-LIBCHROMIUMCONTENT_COMMIT = 'dcd011c56f1e19885bac78ca58a397b0c5c25265'
+LIBCHROMIUMCONTENT_COMMIT = '61d53e9631625fa8e5d5043aabea18b96ed6a950'
 
 ARCH = {
     'cygwin': '32bit',