Switch the about:gpu implementation from an about handler to dom_ui....

chrome/common/url_constants.cc

Index: chrome/common/url_constants.cc
===================================================================
--- chrome/common/url_constants.cc	(revision 65555)
+++ chrome/common/url_constants.cc	(working copy)
@@ -54,6 +54,7 @@
 const char kAboutCreditsURL[] = "about:credits";
 const char kAboutDNSURL[] = "about:dns";
 const char kAboutFlagsURL[] = "about:flags";
+const char kAboutGpuURL[] = "about:gpu";
 const char kAboutGpuCrashURL[] = "about:gpucrash";
 const char kAboutGpuHangURL[] = "about:gpuhang";
 const char kAboutHangURL[] = "about:hang";
@@ -113,6 +114,7 @@
 const char kChromeUIExtensionsHost[] = "extensions";
 const char kChromeUIFavIconHost[] = "favicon";
 const char kChromeUIFlagsHost[] = "flags";
+const char kChromeUIGpuHost[] = "gpu";
 const char kChromeUIHistoryHost[] = "history";
 const char kChromeUIHistory2Host[] = "history2";
 const char kChromeUIInspectorHost[] = "inspector";
@@ -157,6 +159,9 @@
 const char kNetworkViewInternalsURL[] = "chrome://net-internals/";
 const char kNetworkViewCacheURL[] = "chrome://view-http-cache/";
 
+// GPU sub pages
+const char kGpuURL[] = "chrome://gpu/";
+
 // Option sub pages.
 const char kAdvancedOptionsSubPage[] =  "advanced";
 const char kAutoFillSubPage[] = "autoFillOptions";