Remove dependency of power_save_blocker_android on various content bits

content/browser/wake_lock/wake_lock_service_context.cc

 // Copyright 2015 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 "content/browser/wake_lock/wake_lock_service_context.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "build/build_config.h"
 #include "content/browser/power_save_blocker_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/power_save_blocker_factory.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/common/service_registry.h"
 
 namespace content {
 
 WakeLockServiceContext::WakeLockServiceContext(WebContents* web_contents)
     : WebContentsObserver(web_contents), weak_factory_(this) {}
 
 WakeLockServiceContext::~WakeLockServiceContext() {}
 
 void WakeLockServiceContext::CreateService(
     int render_process_id,
     int render_frame_id,
     mojo::InterfaceRequest<blink::mojom::WakeLockService> request) {
   new WakeLockServiceImpl(weak_factory_.GetWeakPtr(), render_process_id,
                           render_frame_id, std::move(request));
 }
 
 void WakeLockServiceContext::RenderFrameDeleted(
     RenderFrameHost* render_frame_host) {
   CancelWakeLock(render_frame_host->GetProcess()->GetID(),
                  render_frame_host->GetRoutingID());
 }
 
+void WakeLockServiceContext::WebContentsDestroyed() {
+#if defined(OS_ANDROID)
+  if (wake_lock_) {
+    static_cast<PowerSaveBlockerImpl*>(wake_lock_.get())
+        ->ClearViewForSleepBlocker();

[ncarter (slow), 2016/06/01 22:01:11]

Now that there are 2 downcasts, consider making wake_lock_ the Impl type, so
that you only have to do the static_cast at CreatePowerSaveBlocker time (where
it's also easier to verify that the cast is safe).

[ncarter (slow), 2016/06/01 22:02:57]

Or don't -- downcasting while assigning a unique_ptr can be a PITA, and it's
probably worse than 2 static_casts.

+  }
+#endif
+}
+
 void WakeLockServiceContext::RequestWakeLock(int render_process_id,
                                              int render_frame_id) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (!RenderFrameHost::FromID(render_process_id, render_frame_id))
     return;
 
   frames_requesting_lock_.insert(
       std::pair<int, int>(render_process_id, render_frame_id));
   UpdateWakeLock();
 }
@@ skipping 14 matching lines @@
   DCHECK(!wake_lock_);
   wake_lock_ = CreatePowerSaveBlocker(
       PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep,
       PowerSaveBlocker::kReasonOther, "Wake Lock API");
 
 #if defined(OS_ANDROID)
   // On Android, additionaly associate the blocker with this WebContents.
   DCHECK(web_contents());
 
   static_cast<PowerSaveBlockerImpl*>(wake_lock_.get())
-      ->InitDisplaySleepBlocker(web_contents());
+      ->InitDisplaySleepBlocker(web_contents()->GetNativeView());
 #endif
 }
 
 void WakeLockServiceContext::RemoveWakeLock() {
   DCHECK(wake_lock_);
   wake_lock_.reset();
 }
 
 void WakeLockServiceContext::UpdateWakeLock() {
   if (!frames_requesting_lock_.empty()) {
     if (!wake_lock_)
       CreateWakeLock();
   } else {
     if (wake_lock_)
       RemoveWakeLock();
   }
 }
 
 }  // namespace content