Revert of Turn on MojoChannel

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 29ec744dc6ca4dfd46a474494abe1c2286654d87..7592d3f8f96b0942eb8fdfded0035bcf1d54c70b 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -800,20 +800,22 @@
     const std::string& channel_id) {
   scoped_refptr<base::SingleThreadTaskRunner> runner =
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO);
-  mojo_channel_token_ = mojo::edk::GenerateRandomToken();
-  mojo::ScopedMessagePipeHandle handle =
-      mojo::edk::CreateParentMessagePipe(mojo_channel_token_);
-
-  // Do NOT expand ifdef or run time condition checks here! Synchronous
-  // IPCs from browser process are banned. It is only narrowly allowed
-  // for Android WebView to maintain backward compatibility.
-  // See crbug.com/526842 for details.
+  if (ShouldUseMojoChannel()) {
+    VLOG(1) << "Mojo Channel is enabled on host";
+    mojo_channel_token_ = mojo::edk::GenerateRandomToken();
+    mojo::ScopedMessagePipeHandle handle =
+        mojo::edk::CreateParentMessagePipe(mojo_channel_token_);
+
+    // Do NOT expand ifdef or run time condition checks here! Synchronous
+    // IPCs from browser process are banned. It is only narrowly allowed
+    // for Android WebView to maintain backward compatibility.
+    // See crbug.com/526842 for details.
 #if defined(OS_ANDROID)
-  if (GetContentClient()->UsingSynchronousCompositing()) {
-    return IPC::SyncChannel::Create(
-        IPC::ChannelMojo::CreateServerFactory(std::move(handle)), this,
-        runner.get(), true, &never_signaled_);
-  }
+    if (GetContentClient()->UsingSynchronousCompositing()) {
+      return IPC::SyncChannel::Create(
+          IPC::ChannelMojo::CreateServerFactory(std::move(handle)), this,
+          runner.get(), true, &never_signaled_);
+    }
 #endif  // OS_ANDROID
 
   std::unique_ptr<IPC::ChannelProxy> channel(
@@ -824,6 +826,25 @@
       content::BrowserThread::IO));
 #endif
   channel->Init(IPC::ChannelMojo::CreateServerFactory(std::move(handle)), true);
+  return channel;
+  }
+
+    // Do NOT expand ifdef or run time condition checks here! See comment above.
+#if defined(OS_ANDROID)
+  if (GetContentClient()->UsingSynchronousCompositing()) {
+    return IPC::SyncChannel::Create(channel_id, IPC::Channel::MODE_SERVER, this,
+                                    runner.get(), true, &never_signaled_);
+  }
+#endif  // OS_ANDROID
+
+  std::unique_ptr<IPC::ChannelProxy> channel(
+      new IPC::ChannelProxy(this, runner.get()));
+#if USE_ATTACHMENT_BROKER
+  IPC::AttachmentBroker::GetGlobal()->RegisterCommunicationChannel(
+      channel.get(), content::BrowserThread::GetMessageLoopProxyForThread(
+      content::BrowserThread::IO));
+#endif
+  channel->Init(channel_id, IPC::Channel::MODE_SERVER, true);
   return channel;
 }
 
@@ -1404,6 +1425,7 @@
     switches::kEnableLinkDisambiguationPopup,
     switches::kEnableLowResTiling,
     switches::kEnableMediaSuspend,
+    switches::kEnableMojoChannel,
     switches::kEnableInbandTextTracks,
     switches::kEnableLCDText,
     switches::kEnableLogging,