Remove ContextProvider::DestroyedOnMainThread.

ContextProvider::DestroyedOnMainThread was used on the main thread
to check when a context bound to different thread had been destroyed.

After crrev.com/1369843002, the only place where DestroyedOnMainThread
is called is on the shared main thread context, that is already bound
to the main thread.

DestroyedOnMainThread and the lock used to protect |destroyed| are no
longer needed.

BUG=544547
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1406923004

Cr-Commit-Position: refs/heads/master@{#355431}

3 files changed, 4 insertions, 21 deletions

diff --git a/ui/compositor/test/in_process_context_factory.cc b/ui/compositor/test/in_process_context_factory.cc
index 1d96e01..5d08817 100644
--- a/ui/compositor/test/in_process_context_factory.cc
+++ b/ui/compositor/test/in_process_context_factory.cc
@@ -178,8 +178,9 @@ void InProcessContextFactory::RemoveReflector(Reflector* reflector) {
 
 scoped_refptr<cc::ContextProvider>
 InProcessContextFactory::SharedMainThreadContextProvider() {
-  if (shared_main_thread_contexts_.get() &&
-      !shared_main_thread_contexts_->DestroyedOnMainThread())
+  if (shared_main_thread_contexts_ &&
+      shared_main_thread_contexts_->ContextGL()->GetGraphicsResetStatusKHR() ==
+          GL_NO_ERROR)
     return shared_main_thread_contexts_;
 
   shared_main_thread_contexts_ = InProcessContextProvider::CreateOffscreen(
diff --git a/ui/compositor/test/in_process_context_provider.cc b/ui/compositor/test/in_process_context_provider.cc
index 92fbf3a..1588da5 100644
--- a/ui/compositor/test/in_process_context_provider.cc
+++ b/ui/compositor/test/in_process_context_provider.cc
@@ -79,8 +79,7 @@ InProcessContextProvider::InProcessContextProvider(
       gpu_memory_buffer_manager_(gpu_memory_buffer_manager),
       image_factory_(image_factory),
       window_(window),
-      debug_name_(debug_name),
-      destroyed_(false) {
+      debug_name_(debug_name) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   context_thread_checker_.DetachFromThread();
 }
@@ -200,13 +199,6 @@ void InProcessContextProvider::DeleteCachedResources() {
   }
 }
 
-bool InProcessContextProvider::DestroyedOnMainThread() {
-  DCHECK(main_thread_checker_.CalledOnValidThread());
-
-  base::AutoLock lock(destroyed_lock_);
-  return destroyed_;
-}
-
 void InProcessContextProvider::SetLostContextCallback(
     const LostContextCallback& lost_context_callback) {
   lost_context_callback_ = lost_context_callback;
@@ -214,12 +206,6 @@ void InProcessContextProvider::SetLostContextCallback(
 
 void InProcessContextProvider::OnLostContext() {
   DCHECK(context_thread_checker_.CalledOnValidThread());
-  {
-    base::AutoLock lock(destroyed_lock_);
-    if (destroyed_)
-      return;
-    destroyed_ = true;
-  }
   if (!lost_context_callback_.is_null())
     base::ResetAndReturn(&lost_context_callback_).Run();
   if (gr_context_)
diff --git a/ui/compositor/test/in_process_context_provider.h b/ui/compositor/test/in_process_context_provider.h
index b728041..c80fb0f 100644
--- a/ui/compositor/test/in_process_context_provider.h
+++ b/ui/compositor/test/in_process_context_provider.h
@@ -50,7 +50,6 @@ class InProcessContextProvider : public cc::ContextProvider {
   base::Lock* GetLock() override;
   void VerifyContexts() override;
   void DeleteCachedResources() override;
-  bool DestroyedOnMainThread() override;
   void SetLostContextCallback(
       const LostContextCallback& lost_context_callback) override;
 
@@ -80,9 +79,6 @@ class InProcessContextProvider : public cc::ContextProvider {
 
   LostContextCallback lost_context_callback_;
 
-  base::Lock destroyed_lock_;
-  bool destroyed_;
-
   base::Lock context_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(InProcessContextProvider);