aw: Do not assume functor will be called on UI thread

android_webview/browser/gl_view_renderer_manager.cc

Index: android_webview/browser/gl_view_renderer_manager.cc
diff --git a/android_webview/browser/gl_view_renderer_manager.cc b/android_webview/browser/gl_view_renderer_manager.cc
index bca0d135f2c8a63f5b74ffde04735a0a53d7fe3a..6c9ab4a8d294cf7ccf0b649b95610c068f82da76 100644
--- a/android_webview/browser/gl_view_renderer_manager.cc
+++ b/android_webview/browser/gl_view_renderer_manager.cc
@@ -5,16 +5,34 @@
 #include "android_webview/browser/gl_view_renderer_manager.h"
 
 #include "base/logging.h"
+#include "base/threading/platform_thread.h"
 
 namespace android_webview {
 
+using base::AutoLock;
+
 GLViewRendererManager::GLViewRendererManager() {}
 
 GLViewRendererManager::~GLViewRendererManager() {}
 
+bool GLViewRendererManager::OnRenderThread() const {
+  AutoLock auto_lock(lock_);
+  return render_thread_.is_equal(base::PlatformThread::CurrentHandle());
+}
+
+void GLViewRendererManager::MarkRenderThread() {
+  lock_.AssertAcquired();
+  if (render_thread_.is_null())
+    render_thread_ = base::PlatformThread::CurrentHandle();
+  DCHECK(render_thread_.is_equal(base::PlatformThread::CurrentHandle()));
+}
+
 GLViewRendererManager::Key GLViewRendererManager::DidDrawGL(
     Key key,
     BrowserViewRenderer* view) {
+  AutoLock auto_lock(lock_);
+  MarkRenderThread();
+
   if (key == mru_list_.end()) {
     DCHECK(mru_list_.end() ==
            std::find(mru_list_.begin(), mru_list_.end(), view));
@@ -28,17 +46,20 @@ GLViewRendererManager::Key GLViewRendererManager::DidDrawGL(
 }
 
 void GLViewRendererManager::NoLongerExpectsDrawGL(Key key) {
+  AutoLock auto_lock(lock_);
   DCHECK(mru_list_.end() != key);
   mru_list_.erase(key);
 }
 
 BrowserViewRenderer* GLViewRendererManager::GetMostRecentlyDrawn() const {
+  AutoLock auto_lock(lock_);
   if (mru_list_.begin() == mru_list_.end())
     return NULL;
   return *mru_list_.begin();
 }
 
 GLViewRendererManager::Key GLViewRendererManager::NullKey() {
+  AutoLock auto_lock(lock_);
   return mru_list_.end();
 }