cc: Remove cc::Thread and cc::ThreadImpl.

cc/trees/proxy.cc

Index: cc/trees/proxy.cc
diff --git a/cc/trees/proxy.cc b/cc/trees/proxy.cc
index fd39ed02369febfae2793d2107608d26a075e617..55a58af445ec783f20621827878632a35fd1ad91 100644
--- a/cc/trees/proxy.cc
+++ b/cc/trees/proxy.cc
@@ -4,31 +4,27 @@
 
 #include "cc/trees/proxy.h"
 
-#include "cc/base/thread.h"
-#include "cc/base/thread_impl.h"
+#include "base/message_loop_proxy.h"
+#include "base/single_thread_task_runner.h"
 
 namespace cc {
 
-Thread* Proxy::MainThread() const { return main_thread_.get(); }
-
-bool Proxy::HasImplThread() const { return impl_thread_; }
+base::SingleThreadTaskRunner* Proxy::MainThreadTaskRunner() const {
+  return main_task_runner_.get();
+}
 
-Thread* Proxy::ImplThread() const { return impl_thread_.get(); }
+bool Proxy::HasImplThread() const { return !!impl_task_runner_.get(); }
 
-Thread* Proxy::CurrentThread() const {
-  if (MainThread() && MainThread()->BelongsToCurrentThread())
-    return MainThread();
-  if (ImplThread() && ImplThread()->BelongsToCurrentThread())
-    return ImplThread();
-  return NULL;
+base::SingleThreadTaskRunner* Proxy::ImplThreadTaskRunner() const {
+  return impl_task_runner_.get();
 }
 
 bool Proxy::IsMainThread() const {
 #ifndef NDEBUG
-  DCHECK(MainThread());
+  DCHECK(main_task_runner_.get());
   if (impl_thread_is_overridden_)
     return false;
-  return MainThread()->BelongsToCurrentThread();
+  return main_task_runner_->BelongsToCurrentThread();
 #else
   return true;
 #endif
@@ -38,7 +34,9 @@ bool Proxy::IsImplThread() const {
 #ifndef NDEBUG
   if (impl_thread_is_overridden_)
     return true;
-  return ImplThread() && ImplThread()->BelongsToCurrentThread();
+  if (!impl_task_runner_.get())
+    return false;
+  return impl_task_runner_->BelongsToCurrentThread();
 #else
   return true;
 #endif
@@ -64,12 +62,13 @@ void Proxy::SetMainThreadBlocked(bool is_main_thread_blocked) {
 }
 #endif
 
-Proxy::Proxy(scoped_ptr<Thread> impl_thread)
-    : main_thread_(ThreadImpl::CreateForCurrentThread()),
+Proxy::Proxy(
+    scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner)
+    : main_task_runner_(base::MessageLoopProxy::current()),
 #ifdef NDEBUG
-      impl_thread_(impl_thread.Pass()) {}
+      impl_task_runner_(impl_task_runner) {}
 #else
-      impl_thread_(impl_thread.Pass()),
+      impl_task_runner_(impl_task_runner),
       impl_thread_is_overridden_(false),
       is_main_thread_blocked_(false) {}
 #endif