Ping watchdog thread during GpuChannel destruction

gpu/command_buffer/service/program_manager.cc

Index: gpu/command_buffer/service/program_manager.cc
diff --git a/gpu/command_buffer/service/program_manager.cc b/gpu/command_buffer/service/program_manager.cc
index 754d5b0630b16d7d450787076dbbfbfd6b3fb257..570e9257bc982a86a71f1720402d74142d298079 100644
--- a/gpu/command_buffer/service/program_manager.cc
+++ b/gpu/command_buffer/service/program_manager.cc
@@ -28,6 +28,7 @@
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "gpu/command_buffer/service/gpu_preferences.h"
 #include "gpu/command_buffer/service/program_cache.h"
+#include "gpu/command_buffer/service/progress_reporter.h"
 #include "gpu/command_buffer/service/shader_manager.h"
 #include "third_party/re2/src/re2/re2.h"
 #include "ui/gl/gl_version_info.h"
@@ -2474,12 +2475,17 @@ ProgramManager::~ProgramManager() {
   DCHECK(programs_.empty());
 }
 
-void ProgramManager::Destroy(bool have_context) {
+void ProgramManager::Destroy(bool have_context,
+                             ProgressReporter* progress_reporter) {
+  DCHECK(progress_reporter);
   have_context_ = have_context;
 
   ProgramDeletionScopedUmaTimeAndRate scoped_histogram(
       base::saturated_cast<int32_t>(programs_.size()));
-  programs_.clear();
+  while (!programs_.empty()) {
+    programs_.erase(programs_.begin());
+    progress_reporter->ReportProgress();
+  }
 }
 
 void ProgramManager::StartTracking(Program* /* program */) {