media: Add BrowserCdmManagerProcessWatcher.

Based on nick@chromium.org's CL: http://crrev.com/1214073015#ps1

Instead of having RenderProcessHostImpl hosts BrowserCdmManager, add
BrowserCdmManagerProcessWatcher, a RenderProcessHostObserver, to keep a
reference to BrowserCdmManager, and manage the entries in
g_browser_cdm_manager_map.

BUG=506188
TEST=Test reenabled.

Review URL: https://codereview.chromium.org/1225083002

Cr-Commit-Position: refs/heads/master@{#338146}

4 files changed, 52 insertions, 37 deletions

diff --git a/content/browser/loader/resource_dispatcher_host_browsertest.cc b/content/browser/loader/resource_dispatcher_host_browsertest.cc
index fdd4b73..b612d30 100644
--- a/content/browser/loader/resource_dispatcher_host_browsertest.cc
+++ b/content/browser/loader/resource_dispatcher_host_browsertest.cc
@@ -308,8 +308,7 @@ IN_PROC_BROWSER_TEST_F(ResourceDispatcherHostBrowserTest,
 // app isn't stripped of debug symbols, this takes about five minutes to
 // complete and isn't conducive to quick turnarounds. As we don't currently
 // strip the app on the build bots, this is bad times.
-// Also disabled on Android (http://crbug.com/506188).
-#if defined(OS_MACOSX) || defined(OS_ANDROID)
+#if defined(OS_MACOSX)
 #define MAYBE_CrossSiteAfterCrash DISABLED_CrossSiteAfterCrash
 #else
 #define MAYBE_CrossSiteAfterCrash CrossSiteAfterCrash
diff --git a/content/browser/media/cdm/browser_cdm_manager.cc b/content/browser/media/cdm/browser_cdm_manager.cc
index 3c4438a..6702e31 100644
--- a/content/browser/media/cdm/browser_cdm_manager.cc
+++ b/content/browser/media/cdm/browser_cdm_manager.cc
@@ -17,7 +17,7 @@
 #include "content/public/browser/permission_type.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
-#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_process_host_observer.h"
 #include "content/public/browser/web_contents.h"
 #include "media/base/browser_cdm.h"
 #include "media/base/browser_cdm_factory.h"
@@ -105,20 +105,55 @@ void CdmPromiseInternal<std::string>::resolve(const std::string& session_id) {
 typedef CdmPromiseInternal<> SimplePromise;
 typedef CdmPromiseInternal<std::string> NewSessionPromise;
 
-}  // namespace
-
 // Render process ID to BrowserCdmManager map.
 typedef std::map<int, BrowserCdmManager*> BrowserCdmManagerMap;
 base::LazyInstance<BrowserCdmManagerMap>::Leaky g_browser_cdm_manager_map =
     LAZY_INSTANCE_INITIALIZER;
 
-BrowserCdmManager* BrowserCdmManager::FromProcess(int render_process_id) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+// Keeps the BrowserCdmManager alive, and in the global map, for as long as the
+// RenderProcessHost is connected to the child process. This class is a
+// self-owned observer.
+class BrowserCdmManagerProcessWatcher : public RenderProcessHostObserver {
+ public:
+  BrowserCdmManagerProcessWatcher(
+      int render_process_id,
+      const scoped_refptr<BrowserCdmManager>& manager)
+      : browser_cdm_manager_(manager) {
+    RenderProcessHost::FromID(render_process_id)->AddObserver(this);
+    CHECK(g_browser_cdm_manager_map.Get()
+              .insert(std::make_pair(render_process_id, manager.get()))
+              .second);
+  }
 
-  if (!g_browser_cdm_manager_map.Get().count(render_process_id))
-    return NULL;
+  // RenderProcessHostObserver:
+  void RenderProcessExited(RenderProcessHost* host,
+                           base::TerminationStatus /* status */,
+                           int /* exit_code */) override {
+    RemoveHostObserverAndDestroy(host);
+  }
+
+  void RenderProcessHostDestroyed(RenderProcessHost* host) override {
+    RemoveHostObserverAndDestroy(host);
+  }
 
-  return g_browser_cdm_manager_map.Get()[render_process_id];
+ private:
+  void RemoveHostObserverAndDestroy(RenderProcessHost* host) {
+    CHECK(g_browser_cdm_manager_map.Get().erase(host->GetID()));
+    host->RemoveObserver(this);
+    delete this;
+  }
+
+  const scoped_refptr<BrowserCdmManager> browser_cdm_manager_;
+};
+
+}  // namespace
+
+// static
+BrowserCdmManager* BrowserCdmManager::FromProcess(int render_process_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  auto& map = g_browser_cdm_manager_map.Get();
+  auto iterator = map.find(render_process_id);
+  return (iterator == map.end()) ? nullptr : iterator->second;
 }
 
 BrowserCdmManager::BrowserCdmManager(
@@ -131,23 +166,18 @@ BrowserCdmManager::BrowserCdmManager(
   DVLOG(1) << __FUNCTION__ << ": " << render_process_id_;
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
+  new BrowserCdmManagerProcessWatcher(render_process_id, this);
+
   if (!task_runner_.get()) {
     task_runner_ =
         BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI);
   }
-
-  DCHECK(!g_browser_cdm_manager_map.Get().count(render_process_id_))
-      << render_process_id_;
-  g_browser_cdm_manager_map.Get()[render_process_id] = this;
 }
 
 BrowserCdmManager::~BrowserCdmManager() {
   DVLOG(1) << __FUNCTION__ << ": " << render_process_id_;
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  DCHECK(g_browser_cdm_manager_map.Get().count(render_process_id_));
-  DCHECK_EQ(this, g_browser_cdm_manager_map.Get()[render_process_id_]);
-
-  g_browser_cdm_manager_map.Get().erase(render_process_id_);
+  DCHECK(g_browser_cdm_manager_map.Get().count(render_process_id_) == 0);
 }
 
 // Makes sure BrowserCdmManager is always deleted on the Browser UI thread.
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 248ed1d..1134556 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -848,8 +848,7 @@ void RenderProcessHostImpl::CreateMessageFilters() {
   AddFilter(browser_demuxer_android_.get());
 #endif
 #if defined(ENABLE_BROWSER_CDMS)
-  browser_cdm_manager_ = new BrowserCdmManager(GetID(), NULL);
-  AddFilter(browser_cdm_manager_.get());
+  AddFilter(new BrowserCdmManager(GetID(), NULL));
 #endif
 
   WebSocketDispatcherHost::GetRequestContextCallback
@@ -1024,7 +1023,10 @@ void RenderProcessHostImpl::SendUpdateValueState(unsigned int target,
 media::BrowserCdm* RenderProcessHostImpl::GetBrowserCdm(int render_frame_id,
                                                         int cdm_id) const {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  return browser_cdm_manager_->GetCdm(render_frame_id, cdm_id);
+  BrowserCdmManager* manager = BrowserCdmManager::FromProcess(GetID());
+  if (!manager)
+    return nullptr;
+  return manager->GetCdm(render_frame_id, cdm_id);
 }
 #endif
 
@@ -1686,9 +1688,6 @@ void RenderProcessHostImpl::Cleanup() {
     // The following members should be cleared in ProcessDied() as well!
     gpu_message_filter_ = NULL;
     message_port_message_filter_ = NULL;
-#if defined(ENABLE_BROWSER_CDMS)
-    browser_cdm_manager_ = NULL;
-#endif
 
     RemoveUserData(kSessionStorageHolderKey);
 
@@ -2129,9 +2128,6 @@ void RenderProcessHostImpl::ProcessDied(bool already_dead,
 
   gpu_message_filter_ = NULL;
   message_port_message_filter_ = NULL;
-#if defined(ENABLE_BROWSER_CDMS)
-  browser_cdm_manager_ = NULL;
-#endif
   RemoveUserData(kSessionStorageHolderKey);
 
   IDMap<IPC::Listener>::iterator iter(&listeners_);
diff --git a/content/browser/renderer_host/render_process_host_impl.h b/content/browser/renderer_host/render_process_host_impl.h
index 8937fd1..e6c2f82 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -248,12 +248,6 @@ class CONTENT_EXPORT RenderProcessHostImpl
   }
 #endif
 
-#if defined(ENABLE_BROWSER_CDMS)
-  const scoped_refptr<BrowserCdmManager>& browser_cdm_manager() {
-    return browser_cdm_manager_;
-  }
-#endif
-
   MessagePortMessageFilter* message_port_message_filter() const {
     return message_port_message_filter_.get();
   }
@@ -460,10 +454,6 @@ class CONTENT_EXPORT RenderProcessHostImpl
   scoped_refptr<BrowserDemuxerAndroid> browser_demuxer_android_;
 #endif
 
-#if defined(ENABLE_BROWSER_CDMS)
-  scoped_refptr<BrowserCdmManager> browser_cdm_manager_;
-#endif
-
 #if defined(ENABLE_WEBRTC)
   base::Callback<void(const std::string&)> webrtc_log_message_callback_;