Add --dump-line-box-trees parameter to content_shell.

content/shell/common/shell_switches.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/shell/common/shell_switches.h"
 
 namespace switches {
 
 // Allow access to external pages during layout tests.
 const char kAllowExternalPages[] = "allow-external-pages";
@@ skipping 12 matching lines @@
 
 // When specified to "enable-leak-detection" command-line option,
 // causes the leak detector to cause immediate crash when found leak.
 const char kCrashOnFailure[] = "crash-on-failure";
 
 // Request the render trees of pages to be dumped as text once they have
 // finished loading. Note that this switch has been deprecated, and the
 // identically functioning |kRunLayoutTest| switch should be used instead.
 const char kDumpRenderTree[] = "dump-render-tree";
 
+// When dump-render-tree is enabled, this causes the line box tree for
+// each LayoutBlockFlow to be dumped as well.
+const char kDumpLineBoxTrees[] = "dump-line-box-trees";
+
 // Expose window.ipcTester object for testing
 const char kExposeIpcEcho[] = "expose-ipc-echo";
 
 // Enable accelerated 2D canvas.
 const char kEnableAccelerated2DCanvas[] = "enable-accelerated-2d-canvas";
 
 // Enable font antialiasing for pixel tests.
 const char kEnableFontAntialiasing[] = "enable-font-antialiasing";
 
 // Enables the leak detection of loading webpages. This allows us to check
@@ skipping 19 matching lines @@
 // This makes us disable some web-platform runtime features so that we test
 // content_shell as if it was a stable release. It is only followed when
 // kRunLayoutTest is set. For the features' level, see
 // http://dev.chromium.org/blink/runtime-enabled-features.
 const char kStableReleaseMode[] = "stable-release-mode";
 
 // Size for the content_shell's host window (i.e. "800x600").
 const char kContentShellHostWindowSize[] = "content-shell-host-window-size";
 
 }  // namespace switches