content: Implement dynamic priorities for raster threads.

base/threading/platform_thread_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/threading/platform_thread.h"
 
 #include <errno.h>
 #include <stddef.h>
 #include <sys/prctl.h>
 #include <sys/resource.h>
@@ skipping 33 matching lines @@
     Java_ThreadUtils_setThreadPriorityAudio(env, PlatformThread::CurrentId());
     return true;
   }
   return false;
 }
 
 bool GetCurrentThreadPriorityForPlatform(ThreadPriority* priority) {
   DCHECK(priority);
   *priority = ThreadPriority::NORMAL;
   JNIEnv* env = base::android::AttachCurrentThread();
-  if (Java_ThreadUtils_isThreadPriorityAudio(
-      env, PlatformThread::CurrentId())) {
+  if (Java_ThreadUtils_isThreadPriorityBackground(
+          env, PlatformThread::CurrentId())) {
+    *priority = ThreadPriority::BACKGROUND;
+    return true;
+  } else if (Java_ThreadUtils_isThreadPriorityNormal(
+                 env, PlatformThread::CurrentId())) {
+    *priority = ThreadPriority::NORMAL;
+    return true;
+  } else if (Java_ThreadUtils_isThreadPriorityAudio(
+                 env, PlatformThread::CurrentId())) {
     *priority = ThreadPriority::REALTIME_AUDIO;
     return true;
   }
   return false;
 }
 
+bool SetChildThreadPriorityInCurrentProcess(PlatformThreadId tid,
+                                            ThreadPriority priority) {
+  // On Android, we set the Normal or Background priority through JNI.
+  // Other priorities are not yet supported by current function.
+  JNIEnv* env = base::android::AttachCurrentThread();
+  if (priority == ThreadPriority::BACKGROUND) {
+    Java_ThreadUtils_setThreadPriorityBackground(env, tid);
+    return true;
+  } else if (priority == ThreadPriority::NORMAL) {
+    Java_ThreadUtils_setThreadPriorityNormal(env, tid);
+    return true;
+  }
+  return false;
+}
+
 }  // namespace internal
 
 void PlatformThread::SetName(const std::string& name) {
   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
   tracked_objects::ThreadData::InitializeThreadContext(name);
 
   // Like linux, on android we can get the thread names to show up in the
   // debugger by setting the process name for the LWP.
   // We don't want to do this for the main thread because that would rename
   // the process, causing tools like killall to stop working.
@@ skipping 22 matching lines @@
   // 1Mb is not enough for some tests (see http://crbug.com/263749 for example).
   return 2 * (1 << 20);  // 2Mb
 #endif
 }
 
 bool RegisterThreadUtils(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace base