Don't schedule more invokeFunctors than necessary.

android_webview/browser/shared_renderer_state.cc

Index: android_webview/browser/shared_renderer_state.cc
diff --git a/android_webview/browser/shared_renderer_state.cc b/android_webview/browser/shared_renderer_state.cc
index 576a8a0cd83920acf0a34a16cff124e506d0d799..fc8fd2c4186771c3e5617f483e134bd950581856 100644
--- a/android_webview/browser/shared_renderer_state.cc
+++ b/android_webview/browser/shared_renderer_state.cc
@@ -51,7 +51,11 @@ bool RequestDrawGLTracker::ShouldRequestOnUiThread(SharedRendererState* state) {
     pending_non_ui_->ResetRequestDrawGLCallback();
     pending_non_ui_ = NULL;
   }
-  if (pending_ui_)
+  // At this time, we could have already called RequestDrawGL on the UI thread,
+  // but the corresponding GL mode process hasn't happened yet. In this case,
+  // don't
+  // schedule another requestDrawGL on the UI thread.
+  if (pending_ui_ || state->has_queued_functor_on_ui_)
     return false;
   pending_ui_ = state;
   return true;
@@ -77,6 +81,7 @@ SharedRendererState::SharedRendererState(
     BrowserViewRenderer* browser_view_renderer)
     : ui_loop_(ui_loop),
       browser_view_renderer_(browser_view_renderer),
+      has_queued_functor_on_ui_(false),
       renderer_manager_key_(GLViewRendererManager::GetInstance()->NullKey()),
       force_commit_(false),
       inside_hardware_release_(false),
@@ -112,6 +117,7 @@ void SharedRendererState::ClientRequestDrawGL() {
 
 void SharedRendererState::DidDrawGLProcess() {
   g_request_draw_gl_tracker.Get().ResetPending();
+  has_queued_functor_on_ui_ = false;
 }
 
 void SharedRendererState::ResetRequestDrawGLCallback() {
@@ -125,6 +131,7 @@ void SharedRendererState::ResetRequestDrawGLCallback() {
 void SharedRendererState::ClientRequestDrawGLOnUI() {
   DCHECK(ui_loop_->BelongsToCurrentThread());
   ResetRequestDrawGLCallback();
+  has_queued_functor_on_ui_ = true;
   if (!browser_view_renderer_->RequestDrawGL(false)) {
     g_request_draw_gl_tracker.Get().ResetPending();
     LOG(ERROR) << "Failed to request GL process. Deadlock likely";
@@ -259,6 +266,16 @@ bool SharedRendererState::ReturnedResourcesEmptyOnUI() const {
 
 void SharedRendererState::DrawGL(AwDrawGLInfo* draw_info) {
   TRACE_EVENT0("android_webview", "DrawFunctor");
+  // kModeProcessNoContext should never happen because we tear down hardware
+  // in onTrimMemory. However that guarantee is maintained outside of chromium
+  // code. Not notifying shared state in kModeProcessNoContext can lead to
+  // immediate deadlock, which is slightly more catastrophic than leaks or
+  // corruption.
+  if (draw_info->mode == AwDrawGLInfo::kModeProcess ||

[boliu, 2014/12/13 01:03:15]

nit: put it after the kModeSync check

[hush (inactive), 2014/12/13 01:17:23]

Done.

+      draw_info->mode == AwDrawGLInfo::kModeProcessNoContext) {
+    DidDrawGLProcess();
+  }
+
   if (draw_info->mode == AwDrawGLInfo::kModeSync) {
     TRACE_EVENT_INSTANT0("android_webview", "kModeSync",
                          TRACE_EVENT_SCOPE_THREAD);
@@ -285,16 +302,6 @@ void SharedRendererState::DrawGL(AwDrawGLInfo* draw_info) {
     LOG(ERROR) << "Received unexpected kModeProcessNoContext";
   }
 
-  // kModeProcessNoContext should never happen because we tear down hardware
-  // in onTrimMemory. However that guarantee is maintained outside of chromium
-  // code. Not notifying shared state in kModeProcessNoContext can lead to
-  // immediate deadlock, which is slightly more catastrophic than leaks or
-  // corruption.
-  if (draw_info->mode == AwDrawGLInfo::kModeProcess ||
-      draw_info->mode == AwDrawGLInfo::kModeProcessNoContext) {
-    DidDrawGLProcess();
-  }
-
   if (IsInsideHardwareRelease()) {
     hardware_renderer_.reset();
     // Flush the idle queue in tear down.