Don't use LazyInstance in chrome/browser/image_decoder.*

chrome/browser/image_decoder.cc

Index: chrome/browser/image_decoder.cc
diff --git a/chrome/browser/image_decoder.cc b/chrome/browser/image_decoder.cc
index 12306d8392893fee0bb4b68d2e09de2ea2094e51..24b4a02058e93c84953059ef78d0943f6161bc73 100644
--- a/chrome/browser/image_decoder.cc
+++ b/chrome/browser/image_decoder.cc
@@ -8,7 +8,6 @@
 
 #include "base/bind.h"
 #include "base/callback.h"
-#include "base/lazy_instance.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "content/public/browser/browser_thread.h"
@@ -20,9 +19,6 @@
 
 namespace {
 
-// static, Leaky to allow access from any thread.
-base::LazyInstance<ImageDecoder>::Leaky g_decoder = LAZY_INSTANCE_INITIALIZER;
-
 const int64_t kMaxImageSizeInBytes =
     static_cast<int64_t>(IPC::Channel::kMaximumMessageSize);
 
@@ -95,9 +91,11 @@ ImageDecoder::ImageRequest::~ImageRequest() {
   ImageDecoder::Cancel(this);
 }
 
-ImageDecoder::ImageDecoder() : image_request_id_counter_(0) {}
-
-ImageDecoder::~ImageDecoder() {}
+// static
+ImageDecoder* ImageDecoder::GetInstance() {
+  static auto image_decoder = new ImageDecoder();

[Nico, 2017/02/02 22:13:19]

style guide says "auto*" for pointers

[scottmg, 2017/02/04 01:44:32]

Huh, I didn't know that. I have some places to fix.

[scottmg, 2017/02/06 20:46:29]

[I was going to make a CL with a link to the style guide to make other places
match this, but I can't find anything in a guide that says that. In the guide
https://google.github.io/styleguide/cppguide.html#auto itself auto is suggested
for `new`, but it doesn't mention preferring auto*.

Way far down in the "Another discussion thread" link on chromium-cpp, Daniel
suggested it and a couple people agreed, but I would say it's not terribly
obvious or codified. I personally think it's reasonable but I'm not sure I feel
strongly enough to wage war upon cxx@ again.]

+  return image_decoder;
+}
 
 // static
 void ImageDecoder::Start(ImageRequest* image_request,
@@ -117,8 +115,8 @@ void ImageDecoder::StartWithOptions(ImageRequest* image_request,
                                     std::vector<uint8_t> image_data,
                                     ImageCodec image_codec,
                                     bool shrink_to_fit) {
-  g_decoder.Get().StartWithOptionsImpl(image_request, std::move(image_data),
-                                       image_codec, shrink_to_fit);
+  ImageDecoder::GetInstance()->StartWithOptionsImpl(
+      image_request, std::move(image_data), image_codec, shrink_to_fit);
 }
 
 // static
@@ -131,6 +129,8 @@ void ImageDecoder::StartWithOptions(ImageRequest* image_request,
                    image_codec, shrink_to_fit);
 }
 
+ImageDecoder::ImageDecoder() : image_request_id_counter_(0) {}
+
 void ImageDecoder::StartWithOptionsImpl(ImageRequest* image_request,
                                         std::vector<uint8_t> image_data,
                                         ImageCodec image_codec,
@@ -173,7 +173,7 @@ void ImageDecoder::StartWithOptionsImpl(ImageRequest* image_request,
 // static
 void ImageDecoder::Cancel(ImageRequest* image_request) {
   DCHECK(image_request);
-  g_decoder.Get().CancelImpl(image_request);
+  ImageDecoder::GetInstance()->CancelImpl(image_request);
 }
 
 void ImageDecoder::CancelImpl(ImageRequest* image_request) {