Enable spare RenderProcessHost to be preinitialized.

chrome/browser/android/warmup_manager.cc

Index: chrome/browser/android/warmup_manager.cc
diff --git a/chrome/browser/android/warmup_manager.cc b/chrome/browser/android/warmup_manager.cc
index e3271e3c6960d5064aeba43804e7a0adbe059ee0..eb06a2ed03d57ebec90e45d736b2596093be7f02 100644
--- a/chrome/browser/android/warmup_manager.cc
+++ b/chrome/browser/android/warmup_manager.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/net/predictor.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_android.h"
+#include "content/public/browser/render_process_host.h"
 #include "jni/WarmupManager_jni.h"
 #include "url/gurl.h"
 
@@ -27,6 +28,14 @@ static void PreconnectUrlAndSubresources(JNIEnv* env,
   }
 }
 
+static void WarmupSpareRenderer(JNIEnv* env,
+                                const JavaParamRef<jclass>& clazz,
+                                const JavaParamRef<jobject>& jprofile) {
+  Profile* profile = ProfileAndroid::FromProfileAndroid(jprofile);
+  if (profile) {
+    content::RenderProcessHost::WarmupSpareRenderProcessHost(profile);
+  }
+}
 
 // Register native methods.
 bool RegisterWarmupManager(JNIEnv* env) {