cc: Set ui/gpu/cc/ipc/upload/raster thread priorities.

cc/raster_worker_pool.cc

Index: cc/raster_worker_pool.cc
diff --git a/cc/raster_worker_pool.cc b/cc/raster_worker_pool.cc
index 11fa5777b8d0c3e6639ad2c23d7522010c887c7f..cc10956af08b8654de5410b075d44a1a3cfbbd58 100644
--- a/cc/raster_worker_pool.cc
+++ b/cc/raster_worker_pool.cc
@@ -13,6 +13,11 @@
 #include "cc/picture_pile_impl.h"
 #include "third_party/skia/include/core/SkDevice.h"
 
+#if defined(OS_ANDROID)
+// TODO(epenner): Move thread priorities to base. (crbug.com/170549)
+#include <sys/resource.h>
+#endif
+
 namespace cc {
 
 namespace {
@@ -77,6 +82,14 @@ RasterWorkerPool::Thread::~Thread() {
   Stop();
 }
 
+void RasterWorkerPool::Thread::Init() {
+#if defined(OS_ANDROID)
+  // TODO(epenner): Move thread priorities to base. (crbug.com/170549)
+  int nice_value = 10; // Idle priority.
+  setpriority(PRIO_PROCESS, base::PlatformThread::CurrentId(), nice_value);
+#endif
+}
+
 RasterWorkerPool::RasterWorkerPool(size_t num_raster_threads) {
   const std::string thread_name_prefix = kRasterThreadNamePrefix;
   while (raster_threads_.size() < num_raster_threads) {