Reland of Pass SequencedTaskRunner to PowerSaveBlocker for ui/file ops

content/browser/power_save_blocker_android.cc

Index: content/browser/power_save_blocker_android.cc
diff --git a/content/browser/power_save_blocker_android.cc b/content/browser/power_save_blocker_android.cc
index 0adcd290d5e024a69d6866cdf0978cd1e4b848d1..4e4c6a2bca80fed568d52f742dc3b11f88a52827 100644
--- a/content/browser/power_save_blocker_android.cc
+++ b/content/browser/power_save_blocker_android.cc
@@ -9,7 +9,6 @@
 #include "content/browser/power_save_blocker_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/android/content_view_core.h"
-#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "jni/PowerSaveBlocker_jni.h"
 #include "ui/android/view_android.h"
@@ -22,7 +21,8 @@ class PowerSaveBlockerImpl::Delegate
     : public base::RefCountedThreadSafe<PowerSaveBlockerImpl::Delegate>,
       public WebContentsObserver {
  public:
-  explicit Delegate(WebContents* web_contents);
+  Delegate(WebContents* web_contents,
+           scoped_refptr<base::SequencedTaskRunner> ui_task_runner);
 
   // Does the actual work to apply or remove the desired power save block.
   void ApplyBlock();
@@ -36,11 +36,15 @@ class PowerSaveBlockerImpl::Delegate
 
   base::android::ScopedJavaGlobalRef<jobject> java_power_save_blocker_;
 
+  scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
+
   DISALLOW_COPY_AND_ASSIGN(Delegate);
 };
 
-PowerSaveBlockerImpl::Delegate::Delegate(WebContents* web_contents)
-    : WebContentsObserver(web_contents) {
+PowerSaveBlockerImpl::Delegate::Delegate(
+    WebContents* web_contents,
+    scoped_refptr<base::SequencedTaskRunner> ui_task_runner)
+    : WebContentsObserver(web_contents), ui_task_runner_(ui_task_runner) {
   JNIEnv* env = AttachCurrentThread();
   java_power_save_blocker_.Reset(Java_PowerSaveBlocker_create(env));
 }
@@ -49,7 +53,7 @@ PowerSaveBlockerImpl::Delegate::~Delegate() {
 }
 
 void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
   base::android::ScopedJavaLocalRef<jobject> java_content_view_core =
       GetContentViewCore();
   if (java_content_view_core.is_null())
@@ -62,7 +66,7 @@ void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
 }
 
 void PowerSaveBlockerImpl::Delegate::RemoveBlock() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
   base::android::ScopedJavaLocalRef<jobject> java_content_view_core =
       GetContentViewCore();
   if (java_content_view_core.is_null())
@@ -87,26 +91,30 @@ PowerSaveBlockerImpl::Delegate::GetContentViewCore() {
   return content_view_core_impl->GetJavaObject();
 }
 
-PowerSaveBlockerImpl::PowerSaveBlockerImpl(PowerSaveBlockerType type,
-                                           Reason reason,
-                                           const std::string& description) {
+PowerSaveBlockerImpl::PowerSaveBlockerImpl(
+    PowerSaveBlockerType type,
+    Reason reason,
+    const std::string& description,
+    scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> blocking_task_runner)
+    : ui_task_runner_(ui_task_runner),
+      blocking_task_runner_(blocking_task_runner) {
   // Don't support kPowerSaveBlockPreventAppSuspension
 }
 
 PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
   if (delegate_.get()) {
-    BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE,
-        base::Bind(&Delegate::RemoveBlock, delegate_));
+    ui_task_runner_->PostTask(FROM_HERE,
+                              base::Bind(&Delegate::RemoveBlock, delegate_));
   }
 }
 
 void PowerSaveBlockerImpl::InitDisplaySleepBlocker(WebContents* web_contents) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
   if (!web_contents)
     return;
 
-  delegate_ = new Delegate(web_contents);
+  delegate_ = new Delegate(web_contents, ui_task_runner_);
   delegate_->ApplyBlock();
 }