Remove dependency of power_save_blocker_android on various content bits

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 4e4c6a2bca80fed568d52f742dc3b11f88a52827..c85eb49c85604fa9956319403bfc30bbd70ba54c 100644
--- a/content/browser/power_save_blocker_android.cc
+++ b/content/browser/power_save_blocker_android.cc
@@ -3,13 +3,11 @@
 // 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"
 
@@ -18,21 +16,22 @@ 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_;
 
@@ -42,9 +41,9 @@ class PowerSaveBlockerImpl::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));
 }
@@ -54,41 +53,23 @@ 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(
@@ -109,15 +90,21 @@ PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
   }
 }
 
-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);
 }