DevTools: introduce devtools/blank url for convenience.

Change-Id: I8013c0c149548069e91df8e3b47228f3b2f0646b
Reviewed-on: https://chromium-review.googlesource.com/691099Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505249}

chrome/browser/ui/webui/devtools_ui.cc

@@ -150,6 +150,14 @@ void DevToolsDataSource::StartDataRequest(
     return;
   }
 
+  // Serve empty page.
+  std::string empty_path_prefix(chrome::kChromeUIDevToolsBlankPath);
+  if (base::StartsWith(path, empty_path_prefix,
+                       base::CompareCase::INSENSITIVE_ASCII)) {
+    callback.Run(new base::RefCountedStaticMemory());
+    return;
+  }
+
   // Serve request from remote location.
   std::string remote_path_prefix(chrome::kChromeUIDevToolsRemotePath);
   remote_path_prefix += "/";

chrome/common/url_constants.cc

@@ -188,6 +188,7 @@ const char kChromeUIDelayedHangUIHost[] = "delayeduithreadhang";
 const char kChromeUIDeviceLogHost[] = "device-log";
 const char kChromeUIDevicesHost[] = "devices";
 const char kChromeUIDevToolsHost[] = "devtools";
+const char kChromeUIDevToolsBlankPath[] = "blank";
 const char kChromeUIDevToolsBundledPath[] = "bundled";
 const char kChromeUIDevToolsCustomPath[] = "custom";
 const char kChromeUIDevToolsRemotePath[] = "remote";

chrome/common/url_constants.h

@@ -176,9 +176,10 @@ extern const char kChromeUIDelayedHangUIHost[];
 extern const char kChromeUIDeviceLogHost[];
 extern const char kChromeUIDevicesHost[];
 extern const char kChromeUIDevToolsHost[];
+extern const char kChromeUIDevToolsBlankPath[];
 extern const char kChromeUIDevToolsBundledPath[];
-extern const char kChromeUIDevToolsRemotePath[];
 extern const char kChromeUIDevToolsCustomPath[];
+extern const char kChromeUIDevToolsRemotePath[];
 extern const char kChromeUIDNSHost[];
 extern const char kChromeUIDomainReliabilityInternalsHost[];
 extern const char kChromeUIDownloadsHost[];