Add m-esr52 at 52.6.0

6 files changed, 1375 insertions, 0 deletions

diff --git a/netwerk/protocol/viewsource/moz.build b/netwerk/protocol/viewsource/moz.build
new file mode 100644
index 000000000..4e3303c40
--- /dev/null
+++ b/netwerk/protocol/viewsource/moz.build
@@ -0,0 +1,21 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    'nsIViewSourceChannel.idl',
+]
+
+XPIDL_MODULE = 'necko_viewsource'
+
+UNIFIED_SOURCES += [
+    'nsViewSourceChannel.cpp',
+    'nsViewSourceHandler.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
+LOCAL_INCLUDES += [
+    '/netwerk/base',
+]
diff --git a/netwerk/protocol/viewsource/nsIViewSourceChannel.idl b/netwerk/protocol/viewsource/nsIViewSourceChannel.idl
new file mode 100644
index 000000000..9ed01ef31
--- /dev/null
+++ b/netwerk/protocol/viewsource/nsIViewSourceChannel.idl
@@ -0,0 +1,38 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIChannel.idl"
+
+[uuid(3e9800f8-edb7-4c9a-9285-09b4f045b019)]
+interface nsIViewSourceChannel : nsIChannel
+{
+    /**
+     * The actual (MIME) content type of the data.
+     *
+     * nsIViewSourceChannel returns a content type of
+     * "application/x-view-source" if you ask it for the contentType
+     * attribute.
+     *
+     * However, callers interested in finding out or setting the
+     * actual content type can utilize this attribute.
+     */
+    attribute ACString originalContentType;
+
+    /**
+     * Whether the channel was created to view the source of a srcdoc document.
+     */
+    readonly attribute boolean isSrcdocChannel;
+
+    /**
+     * Set to indicate the base URI.  If this channel is a srcdoc channel, it
+     * returns the base URI provided by the embedded channel.  It is used to
+     * provide an indication of the base URI in circumstances where it isn't
+     * otherwise recoverable.  Returns null when it isn't set and isn't a
+     * srcdoc channel.
+     */
+    attribute nsIURI baseURI;
+};
+
+
diff --git a/netwerk/protocol/viewsource/nsViewSourceChannel.cpp b/netwerk/protocol/viewsource/nsViewSourceChannel.cpp
new file mode 100644
index 000000000..9ed71c4ef
--- /dev/null
+++ b/netwerk/protocol/viewsource/nsViewSourceChannel.cpp
@@ -0,0 +1,1018 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim:set ts=4 sw=4 sts=4 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsViewSourceChannel.h"
+#include "nsIIOService.h"
+#include "nsMimeTypes.h"
+#include "nsNetUtil.h"
+#include "nsContentUtils.h"
+#include "nsIHttpHeaderVisitor.h"
+#include "nsContentSecurityManager.h"
+#include "nsNullPrincipal.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIInputStreamChannel.h"
+#include "mozilla/DebugOnly.h"
+
+NS_IMPL_ADDREF(nsViewSourceChannel)
+NS_IMPL_RELEASE(nsViewSourceChannel)
+/*
+  This QI uses NS_INTERFACE_MAP_ENTRY_CONDITIONAL to check for
+  non-nullness of mHttpChannel, mCachingChannel, and mUploadChannel.
+*/
+NS_INTERFACE_MAP_BEGIN(nsViewSourceChannel)
+    NS_INTERFACE_MAP_ENTRY(nsIViewSourceChannel)
+    NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
+    NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
+    NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIHttpChannel, mHttpChannel)
+    NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIHttpChannelInternal, mHttpChannelInternal)
+    NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICachingChannel, mCachingChannel)
+    NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICacheInfoChannel, mCacheInfoChannel)
+    NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIApplicationCacheChannel, mApplicationCacheChannel)
+    NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIUploadChannel, mUploadChannel)
+    NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIFormPOSTActionChannel, mPostChannel)
+    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsIRequest, nsIViewSourceChannel)
+    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsIChannel, nsIViewSourceChannel)
+    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIViewSourceChannel)
+NS_INTERFACE_MAP_END
+
+nsresult
+nsViewSourceChannel::Init(nsIURI* uri)
+{
+    mOriginalURI = uri;
+
+    nsAutoCString path;
+    nsresult rv = uri->GetPath(path);
+    if (NS_FAILED(rv))
+      return rv;
+
+    nsCOMPtr<nsIIOService> pService(do_GetIOService(&rv));
+    if (NS_FAILED(rv)) return rv;
+
+    nsAutoCString scheme;
+    rv = pService->ExtractScheme(path, scheme);
+    if (NS_FAILED(rv))
+      return rv;
+
+    // prevent viewing source of javascript URIs (see bug 204779)
+    if (scheme.LowerCaseEqualsLiteral("javascript")) {
+      NS_WARNING("blocking view-source:javascript:");
+      return NS_ERROR_INVALID_ARG;
+    }
+
+    // This function is called from within nsViewSourceHandler::NewChannel2
+    // and sets the right loadInfo right after returning from this function.
+    // Until then we follow the principal of least privilege and use
+    // nullPrincipal as the loadingPrincipal and the least permissive
+    // securityflag.
+    nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+
+    rv = pService->NewChannel2(path,
+                               nullptr, // aOriginCharset
+                               nullptr, // aCharSet
+                               nullptr, // aLoadingNode
+                               nullPrincipal,
+                               nullptr, // aTriggeringPrincipal
+                               nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED,
+                               nsIContentPolicy::TYPE_OTHER,
+                               getter_AddRefs(mChannel));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mIsSrcdocChannel = false;
+
+    mChannel->SetOriginalURI(mOriginalURI);
+    mHttpChannel = do_QueryInterface(mChannel);
+    mHttpChannelInternal = do_QueryInterface(mChannel);
+    mCachingChannel = do_QueryInterface(mChannel);
+    mCacheInfoChannel = do_QueryInterface(mChannel);
+    mApplicationCacheChannel = do_QueryInterface(mChannel);
+    mUploadChannel = do_QueryInterface(mChannel);
+    mPostChannel = do_QueryInterface(mChannel);
+    
+    return NS_OK;
+}
+
+nsresult
+nsViewSourceChannel::InitSrcdoc(nsIURI* aURI,
+                                nsIURI* aBaseURI,
+                                const nsAString &aSrcdoc,
+                                nsILoadInfo* aLoadInfo)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIURI> inStreamURI;
+    // Need to strip view-source: from the URI.  Hardcoded to
+    // about:srcdoc as this is the only permissible URI for srcdoc 
+    // loads
+    rv = NS_NewURI(getter_AddRefs(inStreamURI),
+                   NS_LITERAL_STRING("about:srcdoc"));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = NS_NewInputStreamChannelInternal(getter_AddRefs(mChannel),
+                                          inStreamURI,
+                                          aSrcdoc,
+                                          NS_LITERAL_CSTRING("text/html"),
+                                          aLoadInfo,
+                                          true);
+
+    NS_ENSURE_SUCCESS(rv, rv);
+    mOriginalURI = aURI;
+    mIsSrcdocChannel = true;
+
+    mChannel->SetOriginalURI(mOriginalURI);
+    mHttpChannel = do_QueryInterface(mChannel);
+    mHttpChannelInternal = do_QueryInterface(mChannel);
+    mCachingChannel = do_QueryInterface(mChannel);
+    mCacheInfoChannel = do_QueryInterface(mChannel);
+    mApplicationCacheChannel = do_QueryInterface(mChannel);
+    mUploadChannel = do_QueryInterface(mChannel);
+
+    nsCOMPtr<nsIInputStreamChannel> isc = do_QueryInterface(mChannel);
+    MOZ_ASSERT(isc);
+    isc->SetBaseURI(aBaseURI);
+    return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIRequest methods:
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetName(nsACString &result)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetTransferSize(uint64_t *aTransferSize)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetDecodedBodySize(uint64_t *aDecodedBodySize)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetEncodedBodySize(uint64_t *aEncodedBodySize)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::IsPending(bool *result)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->IsPending(result);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetStatus(nsresult *status)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetStatus(status);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::Cancel(nsresult status)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->Cancel(status);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::Suspend(void)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->Suspend();
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::Resume(void)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->Resume();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIChannel methods:
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetOriginalURI(nsIURI* *aURI)
+{
+    NS_ASSERTION(aURI, "Null out param!");
+    *aURI = mOriginalURI;
+    NS_ADDREF(*aURI);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetOriginalURI(nsIURI* aURI)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+    mOriginalURI = aURI;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetURI(nsIURI* *aURI)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsIURI> uri;
+    nsresult rv = mChannel->GetURI(getter_AddRefs(uri));
+    if (NS_FAILED(rv))
+      return rv;
+
+    // protect ourselves against broken channel implementations
+    if (!uri) {
+      NS_ERROR("inner channel returned NS_OK and a null URI");
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    nsAutoCString spec;
+    rv = uri->GetSpec(spec);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    /* XXX Gross hack -- NS_NewURI goes into an infinite loop on
+       non-flat specs.  See bug 136980 */
+    return NS_NewURI(aURI, nsAutoCString(NS_LITERAL_CSTRING("view-source:")+spec), nullptr);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::Open(nsIInputStream **_retval)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    nsresult rv = NS_MaybeOpenChannelUsingOpen2(mChannel, _retval);
+    if (NS_SUCCEEDED(rv)) {
+        mOpened = true;
+    }
+    return rv;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::Open2(nsIInputStream** aStream)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+    nsCOMPtr<nsILoadInfo> loadInfo = mChannel->GetLoadInfo();
+    if(!loadInfo) {
+        MOZ_ASSERT(loadInfo, "can not enforce security without loadInfo");
+        return NS_ERROR_UNEXPECTED;
+    }
+    // setting the flag on the loadInfo indicates that the underlying
+    // channel will be openend using Open2() and hence performs
+    // the necessary security checks.
+    loadInfo->SetEnforceSecurity(true);
+    return Open(aStream);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::AsyncOpen(nsIStreamListener *aListener, nsISupports *ctxt)
+{
+#ifdef DEBUG
+    {
+    nsCOMPtr<nsILoadInfo> loadInfo = mChannel->GetLoadInfo();
+    MOZ_ASSERT(!loadInfo || loadInfo->GetSecurityMode() == 0 ||
+               loadInfo->GetEnforceSecurity(),
+               "security flags in loadInfo but asyncOpen2() not called");
+    }
+#endif
+
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    mListener = aListener;
+
+    /*
+     * We want to add ourselves to the loadgroup before opening
+     * mChannel, since we want to make sure we're in the loadgroup
+     * when mChannel finishes and fires OnStopRequest()
+     */
+    
+    nsCOMPtr<nsILoadGroup> loadGroup;
+    mChannel->GetLoadGroup(getter_AddRefs(loadGroup));
+    if (loadGroup)
+        loadGroup->AddRequest(static_cast<nsIViewSourceChannel*>
+                                         (this), nullptr);
+    
+    nsresult rv = NS_OK;
+    nsCOMPtr<nsILoadInfo> loadInfo = mChannel->GetLoadInfo();
+    if (loadInfo && loadInfo->GetEnforceSecurity()) {
+        rv = mChannel->AsyncOpen2(this);
+    }
+    else {
+        rv = mChannel->AsyncOpen(this, ctxt);
+    }
+
+    if (NS_FAILED(rv) && loadGroup)
+        loadGroup->RemoveRequest(static_cast<nsIViewSourceChannel*>
+                                            (this),
+                                 nullptr, rv);
+
+    if (NS_SUCCEEDED(rv)) {
+        mOpened = true;
+    }
+    
+    return rv;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::AsyncOpen2(nsIStreamListener *aListener)
+{
+  nsCOMPtr<nsILoadInfo> loadInfo = mChannel->GetLoadInfo();
+  if(!loadInfo) {
+    MOZ_ASSERT(loadInfo, "can not enforce security without loadInfo");
+    return NS_ERROR_UNEXPECTED;
+  }
+  // setting the flag on the loadInfo indicates that the underlying
+  // channel will be openend using AsyncOpen2() and hence performs
+  // the necessary security checks.
+  loadInfo->SetEnforceSecurity(true);
+  return AsyncOpen(aListener, nullptr);
+}
+/*
+ * Both the view source channel and mChannel are added to the
+ * loadgroup.  There should never be more than one request in the
+ * loadgroup that has LOAD_DOCUMENT_URI set.  The one that has this
+ * flag set is the request whose URI is used to refetch the document,
+ * so it better be the viewsource channel.
+ *
+ * Therefore, we need to make sure that
+ * 1) The load flags on mChannel _never_ include LOAD_DOCUMENT_URI
+ * 2) The load flags on |this| include LOAD_DOCUMENT_URI when it was
+ *    set via SetLoadFlags (mIsDocument keeps track of this flag).
+ */
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetLoadFlags(uint32_t *aLoadFlags)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    nsresult rv = mChannel->GetLoadFlags(aLoadFlags);
+    if (NS_FAILED(rv))
+      return rv;
+
+    // This should actually be just LOAD_DOCUMENT_URI but the win32 compiler
+    // fails to deal due to amiguous inheritance.  nsIChannel::LOAD_DOCUMENT_URI
+    // also fails; the Win32 compiler thinks that's supposed to be a method.
+    if (mIsDocument)
+      *aLoadFlags |= ::nsIChannel::LOAD_DOCUMENT_URI;
+
+    return rv;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetLoadFlags(uint32_t aLoadFlags)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    // "View source" always wants the currently cached content.
+    // We also want to have _this_ channel, not mChannel to be the
+    // 'document' channel in the loadgroup. 
+ 
+    // These should actually be just LOAD_FROM_CACHE and LOAD_DOCUMENT_URI but
+    // the win32 compiler fails to deal due to amiguous inheritance.
+    // nsIChannel::LOAD_DOCUMENT_URI/nsIRequest::LOAD_FROM_CACHE also fails; the
+    // Win32 compiler thinks that's supposed to be a method.
+    mIsDocument = (aLoadFlags & ::nsIChannel::LOAD_DOCUMENT_URI) ? true : false;
+
+    nsresult rv = mChannel->SetLoadFlags((aLoadFlags |
+                                          ::nsIRequest::LOAD_FROM_CACHE) &
+                                          ~::nsIChannel::LOAD_DOCUMENT_URI);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+    }
+
+    if (mHttpChannel) {
+       rv = mHttpChannel->SetIsMainDocumentChannel(aLoadFlags & ::nsIChannel::LOAD_DOCUMENT_URI);
+       MOZ_ASSERT(NS_SUCCEEDED(rv));
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetContentType(nsACString &aContentType) 
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    aContentType.Truncate();
+
+    if (mContentType.IsEmpty())
+    {
+        // Get the current content type
+        nsresult rv;
+        nsAutoCString contentType;
+        rv = mChannel->GetContentType(contentType);
+        if (NS_FAILED(rv)) return rv;
+
+        // If we don't know our type, just say so.  The unknown
+        // content decoder will then kick in automatically, and it
+        // will call our SetOriginalContentType method instead of our
+        // SetContentType method to set the type it determines.
+        if (!contentType.Equals(UNKNOWN_CONTENT_TYPE)) {
+          contentType = VIEWSOURCE_CONTENT_TYPE;
+        }
+
+        mContentType = contentType;
+    }
+
+    aContentType = mContentType;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetContentType(const nsACString &aContentType)
+{
+    // Our GetContentType() currently returns VIEWSOURCE_CONTENT_TYPE
+    //
+    // However, during the parsing phase the parser calls our
+    // channel's GetContentType(). Returning the string above trips up
+    // the parser. In order to avoid messy changes and not to have the
+    // parser depend on nsIViewSourceChannel Vidur proposed the
+    // following solution:
+    //
+    // The ViewSourceChannel initially returns a content type of
+    // VIEWSOURCE_CONTENT_TYPE.  Based on this type decisions to
+    // create a viewer for doing a view source are made.  After the
+    // viewer is created, nsLayoutDLF::CreateInstance() calls this
+    // SetContentType() with the original content type.  When it's
+    // time for the parser to find out the content type it will call
+    // our channel's GetContentType() and it will get the original
+    // content type, such as, text/html and everything is kosher from
+    // then on.
+
+    if (!mOpened) {
+        // We do not take hints
+        return NS_ERROR_NOT_AVAILABLE;
+    }
+    
+    mContentType = aContentType;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetContentCharset(nsACString &aContentCharset)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetContentCharset(aContentCharset);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetContentCharset(const nsACString &aContentCharset)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->SetContentCharset(aContentCharset);
+}
+
+// We don't forward these methods becacuse content-disposition isn't whitelisted
+// (see GetResponseHeader/VisitResponseHeaders).
+NS_IMETHODIMP
+nsViewSourceChannel::GetContentDisposition(uint32_t *aContentDisposition)
+{
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetContentDisposition(uint32_t aContentDisposition)
+{
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetContentDispositionFilename(nsAString &aContentDispositionFilename)
+{
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetContentDispositionFilename(const nsAString &aContentDispositionFilename)
+{
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetContentDispositionHeader(nsACString &aContentDispositionHeader)
+{
+    return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetContentLength(int64_t *aContentLength)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetContentLength(aContentLength);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetContentLength(int64_t aContentLength)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->SetContentLength(aContentLength);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetLoadGroup(nsILoadGroup* *aLoadGroup)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetLoadGroup(aLoadGroup);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetLoadGroup(nsILoadGroup* aLoadGroup)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->SetLoadGroup(aLoadGroup);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetOwner(nsISupports* *aOwner)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetOwner(aOwner);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetOwner(nsISupports* aOwner)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->SetOwner(aOwner);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetLoadInfo(nsILoadInfo* *aLoadInfo)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetLoadInfo(aLoadInfo);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetLoadInfo(nsILoadInfo* aLoadInfo)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->SetLoadInfo(aLoadInfo);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetNotificationCallbacks(nsIInterfaceRequestor* *aNotificationCallbacks)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetNotificationCallbacks(aNotificationCallbacks);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetNotificationCallbacks(nsIInterfaceRequestor* aNotificationCallbacks)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->SetNotificationCallbacks(aNotificationCallbacks);
+}
+
+NS_IMETHODIMP 
+nsViewSourceChannel::GetSecurityInfo(nsISupports * *aSecurityInfo)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetSecurityInfo(aSecurityInfo);
+}
+
+// nsIViewSourceChannel methods
+NS_IMETHODIMP
+nsViewSourceChannel::GetOriginalContentType(nsACString &aContentType) 
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    return mChannel->GetContentType(aContentType);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetOriginalContentType(const nsACString &aContentType)
+{
+    NS_ENSURE_TRUE(mChannel, NS_ERROR_FAILURE);
+
+    // clear our cached content-type value
+    mContentType.Truncate();
+
+    return mChannel->SetContentType(aContentType);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetIsSrcdocChannel(bool* aIsSrcdocChannel)
+{
+    *aIsSrcdocChannel = mIsSrcdocChannel;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetBaseURI(nsIURI** aBaseURI)
+{
+  if (mIsSrcdocChannel) {
+    nsCOMPtr<nsIInputStreamChannel> isc = do_QueryInterface(mChannel);
+    if (isc) {
+      return isc->GetBaseURI(aBaseURI);
+    }
+  }
+  *aBaseURI = mBaseURI;
+  NS_IF_ADDREF(*aBaseURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetBaseURI(nsIURI* aBaseURI)
+{
+  mBaseURI = aBaseURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetProtocolVersion(nsACString& aProtocolVersion)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+// nsIRequestObserver methods
+NS_IMETHODIMP
+nsViewSourceChannel::OnStartRequest(nsIRequest *aRequest, nsISupports *aContext)
+{
+    NS_ENSURE_TRUE(mListener, NS_ERROR_FAILURE);
+    // The channel may have gotten redirected... Time to update our info
+    mChannel = do_QueryInterface(aRequest);
+    mHttpChannel = do_QueryInterface(aRequest);
+    mCachingChannel = do_QueryInterface(aRequest);
+    mCacheInfoChannel = do_QueryInterface(mChannel);
+    mUploadChannel = do_QueryInterface(aRequest);
+    
+    return mListener->OnStartRequest(static_cast<nsIViewSourceChannel*>
+                                                (this),
+                                     aContext);
+}
+
+
+NS_IMETHODIMP
+nsViewSourceChannel::OnStopRequest(nsIRequest *aRequest, nsISupports* aContext,
+                               nsresult aStatus)
+{
+    NS_ENSURE_TRUE(mListener, NS_ERROR_FAILURE);
+    if (mChannel)
+    {
+        nsCOMPtr<nsILoadGroup> loadGroup;
+        mChannel->GetLoadGroup(getter_AddRefs(loadGroup));
+        if (loadGroup)
+        {
+            loadGroup->RemoveRequest(static_cast<nsIViewSourceChannel*>
+                                                (this),
+                                     nullptr, aStatus);
+        }
+    }
+    return mListener->OnStopRequest(static_cast<nsIViewSourceChannel*>
+                                               (this),
+                                    aContext, aStatus);
+}
+
+
+// nsIStreamListener methods
+NS_IMETHODIMP
+nsViewSourceChannel::OnDataAvailable(nsIRequest *aRequest, nsISupports* aContext,
+                                     nsIInputStream *aInputStream,
+                                     uint64_t aSourceOffset,
+                                     uint32_t aLength) 
+{
+    NS_ENSURE_TRUE(mListener, NS_ERROR_FAILURE);
+    return mListener->OnDataAvailable(static_cast<nsIViewSourceChannel*>
+                                                 (this),
+                                      aContext, aInputStream,
+                                      aSourceOffset, aLength);
+}
+
+
+// nsIHttpChannel methods
+
+// We want to forward most of nsIHttpChannel over to mHttpChannel, but we want
+// to override GetRequestHeader and VisitHeaders. The reason is that we don't
+// want various headers like Link: and Refresh: applying to view-source.
+NS_IMETHODIMP
+nsViewSourceChannel::GetChannelId(nsACString& aChannelId)
+{
+  return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+      mHttpChannel->GetChannelId(aChannelId);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetChannelId(const nsACString& aChannelId)
+{
+  return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+      mHttpChannel->SetChannelId(aChannelId);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetTopLevelContentWindowId(uint64_t *aWindowId)
+{
+  return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+      mHttpChannel->GetTopLevelContentWindowId(aWindowId);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetTopLevelContentWindowId(uint64_t aWindowId)
+{
+  return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+      mHttpChannel->SetTopLevelContentWindowId(aWindowId);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetRequestMethod(nsACString & aRequestMethod)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetRequestMethod(aRequestMethod);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetRequestMethod(const nsACString & aRequestMethod)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetRequestMethod(aRequestMethod);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetReferrer(nsIURI * *aReferrer)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetReferrer(aReferrer);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetReferrer(nsIURI * aReferrer)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetReferrer(aReferrer);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetReferrerPolicy(uint32_t *aReferrerPolicy)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetReferrerPolicy(aReferrerPolicy);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetReferrerWithPolicy(nsIURI * aReferrer,
+                                           uint32_t aReferrerPolicy)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetReferrerWithPolicy(aReferrer, aReferrerPolicy);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetRequestHeader(const nsACString & aHeader,
+                                      nsACString & aValue)
+{
+    aValue.Truncate();
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetRequestHeader(aHeader, aValue);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetRequestHeader(const nsACString & aHeader,
+                                      const nsACString & aValue,
+                                      bool aMerge)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetRequestHeader(aHeader, aValue, aMerge);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetEmptyRequestHeader(const nsACString & aHeader)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetEmptyRequestHeader(aHeader);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::VisitRequestHeaders(nsIHttpHeaderVisitor *aVisitor)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->VisitRequestHeaders(aVisitor);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::VisitNonDefaultRequestHeaders(nsIHttpHeaderVisitor *aVisitor)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->VisitNonDefaultRequestHeaders(aVisitor);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetAllowPipelining(bool *aAllowPipelining)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetAllowPipelining(aAllowPipelining);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetAllowPipelining(bool aAllowPipelining)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetAllowPipelining(aAllowPipelining);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetAllowSTS(bool *aAllowSTS)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetAllowSTS(aAllowSTS);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetAllowSTS(bool aAllowSTS)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetAllowSTS(aAllowSTS);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetRedirectionLimit(uint32_t *aRedirectionLimit)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetRedirectionLimit(aRedirectionLimit);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetRedirectionLimit(uint32_t aRedirectionLimit)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetRedirectionLimit(aRedirectionLimit);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetResponseStatus(uint32_t *aResponseStatus)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetResponseStatus(aResponseStatus);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetResponseStatusText(nsACString & aResponseStatusText)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetResponseStatusText(aResponseStatusText);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetRequestSucceeded(bool *aRequestSucceeded)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetRequestSucceeded(aRequestSucceeded);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetResponseHeader(const nsACString & aHeader,
+                                       nsACString & aValue)
+{
+    aValue.Truncate();
+    if (!mHttpChannel)
+        return NS_ERROR_NULL_POINTER;
+
+    if (!aHeader.Equals(NS_LITERAL_CSTRING("Content-Type"),
+                        nsCaseInsensitiveCStringComparator()) &&
+        !aHeader.Equals(NS_LITERAL_CSTRING("Content-Security-Policy"),
+                        nsCaseInsensitiveCStringComparator()) &&
+        !aHeader.Equals(NS_LITERAL_CSTRING("Content-Security-Policy-Report-Only"),
+                        nsCaseInsensitiveCStringComparator()) &&
+        !aHeader.Equals(NS_LITERAL_CSTRING("X-Frame-Options"),
+                        nsCaseInsensitiveCStringComparator())) {
+        return NS_OK;
+    }
+
+    return mHttpChannel->GetResponseHeader(aHeader, aValue);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetResponseHeader(const nsACString & header,
+                                       const nsACString & value, bool merge)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetResponseHeader(header, value, merge);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::VisitResponseHeaders(nsIHttpHeaderVisitor *aVisitor)
+{
+    if (!mHttpChannel)
+        return NS_ERROR_NULL_POINTER;
+
+    NS_NAMED_LITERAL_CSTRING(contentTypeStr, "Content-Type");
+    nsAutoCString contentType;
+    nsresult rv =
+        mHttpChannel->GetResponseHeader(contentTypeStr, contentType);
+    if (NS_SUCCEEDED(rv))
+        aVisitor->VisitHeader(contentTypeStr, contentType);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetOriginalResponseHeader(const nsACString & aHeader,
+                                               nsIHttpHeaderVisitor *aVisitor)
+{
+    nsAutoCString value;
+    nsresult rv = GetResponseHeader(aHeader, value);
+    if (NS_FAILED(rv)) {
+        return rv;
+    }
+    aVisitor->VisitHeader(aHeader, value);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::VisitOriginalResponseHeaders(nsIHttpHeaderVisitor *aVisitor)
+{
+    return VisitResponseHeaders(aVisitor);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::IsNoStoreResponse(bool *_retval)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->IsNoStoreResponse(_retval);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::IsNoCacheResponse(bool *_retval)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->IsNoCacheResponse(_retval);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::IsPrivateResponse(bool *_retval)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->IsPrivateResponse(_retval);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::RedirectTo(nsIURI *uri)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->RedirectTo(uri);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetRequestContextID(nsID *_retval)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetRequestContextID(_retval);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetRequestContextID(const nsID rcid)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetRequestContextID(rcid);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::GetIsMainDocumentChannel(bool* aValue)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->GetIsMainDocumentChannel(aValue);
+}
+
+NS_IMETHODIMP
+nsViewSourceChannel::SetIsMainDocumentChannel(bool aValue)
+{
+    return !mHttpChannel ? NS_ERROR_NULL_POINTER :
+        mHttpChannel->SetIsMainDocumentChannel(aValue);
+}
+
+// Have to manually forward since these are [notxpcom]
+void
+nsViewSourceChannel::SetCorsPreflightParameters(const nsTArray<nsCString>& aUnsafeHeaders)
+{
+  mHttpChannelInternal->SetCorsPreflightParameters(aUnsafeHeaders);
+}
+
+mozilla::net::nsHttpChannel *
+nsViewSourceChannel::QueryHttpChannelImpl()
+{
+  return mHttpChannelInternal->QueryHttpChannelImpl();
+}
diff --git a/netwerk/protocol/viewsource/nsViewSourceChannel.h b/netwerk/protocol/viewsource/nsViewSourceChannel.h
new file mode 100644
index 000000000..45e561aa7
--- /dev/null
+++ b/netwerk/protocol/viewsource/nsViewSourceChannel.h
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsViewSourceChannel_h___
+#define nsViewSourceChannel_h___
+
+#include "nsString.h"
+#include "nsCOMPtr.h"
+#include "nsIViewSourceChannel.h"
+#include "nsIURI.h"
+#include "nsIStreamListener.h"
+#include "nsIHttpChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsICachingChannel.h"
+#include "nsIApplicationCacheChannel.h"
+#include "nsIFormPOSTActionChannel.h"
+#include "mozilla/Attributes.h"
+
+class nsViewSourceChannel final : public nsIViewSourceChannel,
+                                  public nsIStreamListener,
+                                  public nsIHttpChannel,
+                                  public nsIHttpChannelInternal,
+                                  public nsICachingChannel,
+                                  public nsIApplicationCacheChannel,
+                                  public nsIFormPOSTActionChannel
+{
+
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIREQUEST
+    NS_DECL_NSICHANNEL
+    NS_DECL_NSIVIEWSOURCECHANNEL
+    NS_DECL_NSISTREAMLISTENER
+    NS_DECL_NSIREQUESTOBSERVER
+    NS_DECL_NSIHTTPCHANNEL
+    NS_FORWARD_SAFE_NSICACHEINFOCHANNEL(mCacheInfoChannel)
+    NS_FORWARD_SAFE_NSICACHINGCHANNEL(mCachingChannel)
+    NS_FORWARD_SAFE_NSIAPPLICATIONCACHECHANNEL(mApplicationCacheChannel)
+    NS_FORWARD_SAFE_NSIAPPLICATIONCACHECONTAINER(mApplicationCacheChannel)
+    NS_FORWARD_SAFE_NSIUPLOADCHANNEL(mUploadChannel)
+    NS_FORWARD_SAFE_NSIFORMPOSTACTIONCHANNEL(mPostChannel)
+    NS_FORWARD_SAFE_NSIHTTPCHANNELINTERNAL(mHttpChannelInternal)
+
+    // nsViewSourceChannel methods:
+    nsViewSourceChannel()
+        : mIsDocument(false)
+        , mOpened(false) {}
+
+    nsresult Init(nsIURI* uri);
+
+    nsresult InitSrcdoc(nsIURI* aURI,
+                        nsIURI* aBaseURI,
+                        const nsAString &aSrcdoc,
+                        nsILoadInfo* aLoadInfo);
+
+protected:
+    ~nsViewSourceChannel() {}
+
+    nsCOMPtr<nsIChannel>        mChannel;
+    nsCOMPtr<nsIHttpChannel>    mHttpChannel;
+    nsCOMPtr<nsIHttpChannelInternal>    mHttpChannelInternal;
+    nsCOMPtr<nsICachingChannel> mCachingChannel;
+    nsCOMPtr<nsICacheInfoChannel> mCacheInfoChannel;
+    nsCOMPtr<nsIApplicationCacheChannel> mApplicationCacheChannel;
+    nsCOMPtr<nsIUploadChannel>  mUploadChannel;
+    nsCOMPtr<nsIFormPOSTActionChannel> mPostChannel;
+    nsCOMPtr<nsIStreamListener> mListener;
+    nsCOMPtr<nsIURI>            mOriginalURI;
+    nsCOMPtr<nsIURI>            mBaseURI;
+    nsCString                   mContentType;
+    bool                        mIsDocument; // keeps track of the LOAD_DOCUMENT_URI flag
+    bool                        mOpened;
+    bool                        mIsSrcdocChannel;
+};
+
+#endif /* nsViewSourceChannel_h___ */
diff --git a/netwerk/protocol/viewsource/nsViewSourceHandler.cpp b/netwerk/protocol/viewsource/nsViewSourceHandler.cpp
new file mode 100644
index 000000000..e8d4711d8
--- /dev/null
+++ b/netwerk/protocol/viewsource/nsViewSourceHandler.cpp
@@ -0,0 +1,175 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim:set ts=4 sw=4 sts=4 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsViewSourceHandler.h"
+#include "nsViewSourceChannel.h"
+#include "nsNetUtil.h"
+#include "nsSimpleNestedURI.h"
+
+#define VIEW_SOURCE "view-source"
+
+namespace mozilla {
+namespace net {
+
+////////////////////////////////////////////////////////////////////////////////
+
+NS_IMPL_ISUPPORTS(nsViewSourceHandler, nsIProtocolHandler)
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIProtocolHandler methods:
+
+NS_IMETHODIMP
+nsViewSourceHandler::GetScheme(nsACString &result)
+{
+    result.AssignLiteral(VIEW_SOURCE);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceHandler::GetDefaultPort(int32_t *result)
+{
+    *result = -1;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceHandler::GetProtocolFlags(uint32_t *result)
+{
+    *result = URI_NORELATIVE | URI_NOAUTH | URI_DANGEROUS_TO_LOAD |
+        URI_NON_PERSISTABLE;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceHandler::NewURI(const nsACString &aSpec,
+                            const char *aCharset,
+                            nsIURI *aBaseURI,
+                            nsIURI **aResult)
+{
+    *aResult = nullptr;
+
+    // Extract inner URL and normalize to ASCII.  This is done to properly
+    // support IDN in cases like "view-source:http://www.szalagavató.hu/"
+
+    int32_t colon = aSpec.FindChar(':');
+    if (colon == kNotFound)
+        return NS_ERROR_MALFORMED_URI;
+
+    nsCOMPtr<nsIURI> innerURI;
+    nsresult rv = NS_NewURI(getter_AddRefs(innerURI),
+                            Substring(aSpec, colon + 1), aCharset, aBaseURI);
+    if (NS_FAILED(rv))
+        return rv;
+
+    nsAutoCString asciiSpec;
+    rv = innerURI->GetAsciiSpec(asciiSpec);
+    if (NS_FAILED(rv))
+        return rv;
+
+    // put back our scheme and construct a simple-uri wrapper
+
+    asciiSpec.Insert(VIEW_SOURCE ":", 0);
+
+    // We can't swap() from an RefPtr<nsSimpleNestedURI> to an nsIURI**,
+    // sadly.
+    nsSimpleNestedURI* ourURI = new nsSimpleNestedURI(innerURI);
+    nsCOMPtr<nsIURI> uri = ourURI;
+    if (!uri)
+        return NS_ERROR_OUT_OF_MEMORY;
+
+    rv = ourURI->SetSpec(asciiSpec);
+    if (NS_FAILED(rv))
+        return rv;
+
+    // Make the URI immutable so it's impossible to get it out of sync
+    // with its inner URI.
+    ourURI->SetMutable(false);
+
+    uri.swap(*aResult);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsViewSourceHandler::NewChannel2(nsIURI* uri,
+                                 nsILoadInfo* aLoadInfo,
+                                 nsIChannel** result)
+{
+    NS_ENSURE_ARG_POINTER(uri);
+    nsViewSourceChannel *channel = new nsViewSourceChannel();
+    if (!channel)
+        return NS_ERROR_OUT_OF_MEMORY;
+    NS_ADDREF(channel);
+
+    nsresult rv = channel->Init(uri);
+    if (NS_FAILED(rv)) {
+        NS_RELEASE(channel);
+        return rv;
+    }
+
+    // set the loadInfo on the new channel
+    rv = channel->SetLoadInfo(aLoadInfo);
+    if (NS_FAILED(rv)) {
+        NS_RELEASE(channel);
+        return rv;
+    }
+
+    *result = static_cast<nsIViewSourceChannel*>(channel);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsViewSourceHandler::NewChannel(nsIURI* uri, nsIChannel* *result)
+{
+    return NewChannel2(uri, nullptr, result);
+}
+
+nsresult
+nsViewSourceHandler::NewSrcdocChannel(nsIURI *aURI,
+                                      nsIURI *aBaseURI,
+                                      const nsAString &aSrcdoc,
+                                      nsILoadInfo* aLoadInfo,
+                                      nsIChannel** outChannel)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+    RefPtr<nsViewSourceChannel> channel = new nsViewSourceChannel();
+
+    nsresult rv = channel->InitSrcdoc(aURI, aBaseURI, aSrcdoc, aLoadInfo);
+    if (NS_FAILED(rv)) {
+        return rv;
+    }
+
+    *outChannel = static_cast<nsIViewSourceChannel*>(channel.forget().take());
+    return NS_OK;
+}
+
+NS_IMETHODIMP 
+nsViewSourceHandler::AllowPort(int32_t port, const char *scheme, bool *_retval)
+{
+    // don't override anything.  
+    *_retval = false;
+    return NS_OK;
+}
+
+nsViewSourceHandler::nsViewSourceHandler()
+{
+    gInstance = this;
+}
+
+nsViewSourceHandler::~nsViewSourceHandler()
+{
+    gInstance = nullptr;
+}
+
+nsViewSourceHandler* nsViewSourceHandler::gInstance = nullptr;
+
+nsViewSourceHandler*
+nsViewSourceHandler::GetInstance()
+{
+    return gInstance;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/protocol/viewsource/nsViewSourceHandler.h b/netwerk/protocol/viewsource/nsViewSourceHandler.h
new file mode 100644
index 000000000..76f7c8d01
--- /dev/null
+++ b/netwerk/protocol/viewsource/nsViewSourceHandler.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsViewSourceHandler_h___
+#define nsViewSourceHandler_h___
+
+#include "nsIProtocolHandler.h"
+#include "nsNetUtil.h"
+#include "mozilla/Attributes.h"
+
+class nsILoadInfo;
+
+namespace mozilla {
+namespace net {
+
+class nsViewSourceHandler final : public nsIProtocolHandler
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIPROTOCOLHANDLER
+
+    nsViewSourceHandler();
+
+    // Creates a new nsViewSourceChannel to view the source of an about:srcdoc
+    // URI with contents specified by srcdoc.
+    nsresult NewSrcdocChannel(nsIURI *aURI,
+                              nsIURI *aBaseURI,
+                              const nsAString &aSrcdoc,
+                              nsILoadInfo *aLoadInfo,
+                              nsIChannel** outChannel);
+
+    static nsViewSourceHandler* GetInstance();
+
+private:
+    ~nsViewSourceHandler();
+
+    static nsViewSourceHandler* gInstance;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif /* !defined( nsViewSourceHandler_h___ ) */