Revert of Remove about:srcdoc url conversion.

content/browser/child_process_security_policy_impl.cc

Index: content/browser/child_process_security_policy_impl.cc
diff --git a/content/browser/child_process_security_policy_impl.cc b/content/browser/child_process_security_policy_impl.cc
index 3c207c2c185162d81e83cfdc34138da57563d56f..f1aa1c74d71df72530020a7be37b54ab32fee7f7 100644
--- a/content/browser/child_process_security_policy_impl.cc
+++ b/content/browser/child_process_security_policy_impl.cc
@@ -626,8 +626,8 @@
     return false;  // Can't request invalid URLs.
 
   if (IsPseudoScheme(url.scheme())) {
-    // Every child process can request <about:blank> and <about:srcdoc>.
-    if (url == url::kAboutBlankURL || url == kAboutSrcDocURL)
+    // Every child process can request <about:blank>.
+    if (base::LowerCaseEqualsASCII(url.spec(), url::kAboutBlankURL))
       return true;
     // URLs like <about:version>, <about:crash>, <view-source:...> shouldn't be
     // requestable by any child process.  Also, this case covers
@@ -664,10 +664,9 @@
   if (!url.is_valid())
     return false;  // Can't commit invalid URLs.
 
-  // Of all the pseudo schemes, only about:blank and about:srcdoc are allowed to
-  // commit.
+  // Of all the pseudo schemes, only about:blank is allowed to commit.
   if (IsPseudoScheme(url.scheme()))
-    return url == url::kAboutBlankURL || url == kAboutSrcDocURL;
+    return base::LowerCaseEqualsASCII(url.spec(), url::kAboutBlankURL);
 
   // Blob and filesystem URLs require special treatment; validate the inner
   // origin they embed.
@@ -718,10 +717,6 @@
     return true;
   }
 
-  // about:srcdoc cannot be used as an origin
-  if (url == kAboutSrcDocURL)
-    return false;
-
   // If this process can commit |url|, it can use |url| as an origin for
   // outbound requests.
   if (CanCommitURL(child_id, url))