aw: Improve idle task scheduling

Three related changes:
* Only run idle tasks in the queue, not newly added ones.
* Move g_request_pending logic to SharedRendererState. This
  allows pending tasks to be cancelled correctly.
* Wait for kModeProcess to happen first before trying to
  request another to avoid a queue of pending tasks.

BUG=401712

Review URL: https://codereview.chromium.org/444173003

Cr-Commit-Position: refs/heads/master@{#288285}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288285 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 15 insertions, 2 deletions

diff --git a/android_webview/native/aw_contents.cc b/android_webview/native/aw_contents.cc
index fdddf9f..0803f75 100644
--- a/android_webview/native/aw_contents.cc
+++ b/android_webview/native/aw_contents.cc
@@ -362,11 +362,24 @@ void AwContents::DrawGL(AwDrawGLInfo* draw_info) {
           : ScopedAppGLStateRestore::MODE_RESOURCE_MANAGEMENT);
   ScopedAllowGL allow_gl;
 
+  if (draw_info->mode == AwDrawGLInfo::kModeProcessNoContext) {
+    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) {
+    shared_renderer_state_.DidDrawGLProcess();
+  }
+
   if (shared_renderer_state_.IsInsideHardwareRelease()) {
     hardware_renderer_.reset();
     // Flush the idle queue in tear down.
-    DeferredGpuCommandService::GetInstance()->PerformIdleWork(true);
-    DCHECK(!DeferredGpuCommandService::GetInstance()->HasIdleWork());
+    DeferredGpuCommandService::GetInstance()->PerformAllIdleWork();
     return;
   }