Remove dependency of power_save_blocker_android on various content bits

content/browser/power_save_blocker_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/android/jni_android.h"
+#include "base/bind.h"
+#include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
-#include "content/browser/android/content_view_core_impl.h"
 #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/web_contents_observer.h"
 #include "jni/PowerSaveBlocker_jni.h"
 #include "ui/android/view_android.h"
 
 namespace content {
 
 using base::android::AttachCurrentThread;
 
 class PowerSaveBlockerImpl::Delegate
-    : public base::RefCountedThreadSafe<PowerSaveBlockerImpl::Delegate>,
-      public WebContentsObserver {
+    : public base::RefCountedThreadSafe<PowerSaveBlockerImpl::Delegate> {
  public:
-  Delegate(WebContents* web_contents,
+  Delegate(ui::ViewAndroid* view_android,
            scoped_refptr<base::SequencedTaskRunner> ui_task_runner);
 
   // Does the actual work to apply or remove the desired power save block.
   void ApplyBlock();
   void RemoveBlock();
 
+  void ClearView() { view_android_ = nullptr; }
+
  private:
   friend class base::RefCountedThreadSafe<Delegate>;
-  ~Delegate() override;
+  ~Delegate();
 
-  base::android::ScopedJavaLocalRef<jobject> GetContentViewCore();
+  ui::ViewAndroid* view_android_;
 
   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,
+    ui::ViewAndroid* view_android,
     scoped_refptr<base::SequencedTaskRunner> ui_task_runner)
-    : WebContentsObserver(web_contents), ui_task_runner_(ui_task_runner) {
+    : view_android_(view_android), ui_task_runner_(ui_task_runner) {
   JNIEnv* env = AttachCurrentThread();
   java_power_save_blocker_.Reset(Java_PowerSaveBlocker_create(env));
 }
 
 PowerSaveBlockerImpl::Delegate::~Delegate() {
 }
 
 void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
   DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
-  base::android::ScopedJavaLocalRef<jobject> java_content_view_core =
-      GetContentViewCore();
-  if (java_content_view_core.is_null())
-    return;
 
   ScopedJavaLocalRef<jobject> obj(java_power_save_blocker_);
   JNIEnv* env = AttachCurrentThread();
-  Java_PowerSaveBlocker_applyBlock(env, obj.obj(),
-                                   java_content_view_core.obj());
+  if (view_android_ && !view_android_->GetViewAndroidDelegate().is_null()) {

[boliu, 2016/06/01 21:37:07]

the is_null check isn't actually "safe". in theory gc could run between this
line and the body, and collect the object. So to do this safely, need to save
the ScopedJavaLocalRef as a local variable, check is_null, and then call obj()
to use it

on the other hand, it's safe to assume GetViewAndroidDelegate() never returns
null object, so maybe just skip this check altogether?

[scottmg, 2016/06/01 21:44:42]

Thanks, removed.

+    Java_PowerSaveBlocker_applyBlock(
+        env, obj.obj(), view_android_->GetViewAndroidDelegate().obj());
+  }
 }
 
 void PowerSaveBlockerImpl::Delegate::RemoveBlock() {
   DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
-  base::android::ScopedJavaLocalRef<jobject> java_content_view_core =
-      GetContentViewCore();
-  if (java_content_view_core.is_null())
-    return;
-
   ScopedJavaLocalRef<jobject> obj(java_power_save_blocker_);
   JNIEnv* env = AttachCurrentThread();
-  Java_PowerSaveBlocker_removeBlock(env, obj.obj(),
-                                    java_content_view_core.obj());
-}
-
-base::android::ScopedJavaLocalRef<jobject>
-PowerSaveBlockerImpl::Delegate::GetContentViewCore() {
-  if (!web_contents())
-    return base::android::ScopedJavaLocalRef<jobject>();
-
-  ContentViewCoreImpl* content_view_core_impl =
-      ContentViewCoreImpl::FromWebContents(web_contents());
-  if (!content_view_core_impl)
-    return base::android::ScopedJavaLocalRef<jobject>();
-
-  return content_view_core_impl->GetJavaObject();
+  if (view_android_ && !view_android_->GetViewAndroidDelegate().is_null()) {
+    Java_PowerSaveBlocker_removeBlock(
+        env, obj.obj(), view_android_->GetViewAndroidDelegate().obj());
+  }
 }
 
 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()) {
     ui_task_runner_->PostTask(FROM_HERE,
                               base::Bind(&Delegate::RemoveBlock, delegate_));
   }
 }
 
-void PowerSaveBlockerImpl::InitDisplaySleepBlocker(WebContents* web_contents) {
+void PowerSaveBlockerImpl::InitDisplaySleepBlocker(
+    ui::ViewAndroid* view_android) {
   DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
-  if (!web_contents)
+  if (!view_android)
     return;
 
-  delegate_ = new Delegate(web_contents, ui_task_runner_);
+  delegate_ = new Delegate(view_android, ui_task_runner_);
   delegate_->ApplyBlock();
 }
 
+void PowerSaveBlockerImpl::ClearViewForSleepBlocker() {
+  delegate_->RemoveBlock();
+  delegate_->ClearView();
+}
+
 bool RegisterPowerSaveBlocker(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content