Revert 148272 - Refactor the wallpaper encoding to another file/class.

chrome/browser/ui/webui/options2/chromeos/wallpaper_source.cc

Index: chrome/browser/ui/webui/options2/chromeos/wallpaper_source.cc
===================================================================
--- chrome/browser/ui/webui/options2/chromeos/wallpaper_source.cc	(revision 148277)
+++ chrome/browser/ui/webui/options2/chromeos/wallpaper_source.cc	(working copy)
@@ -7,16 +7,92 @@
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/shell.h"
 #include "base/debug/trace_event.h"
+#include "base/synchronization/cancellation_flag.h"
+#include "base/threading/worker_pool.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
-#include "chrome/browser/ui/webui/options2/chromeos/simple_png_encoder.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "grit/ui_resources.h"
 #include "net/base/mime_util.h"
+#include "ui/gfx/codec/png_codec.h"
+#include "ui/gfx/size.h"
+#include "ui/gfx/skia_util.h"
 
+extern "C" {
+#if defined(USE_SYSTEM_ZLIB)
+#include <zlib.h>
+#else
+#include "third_party/zlib/zlib.h"
+#endif
+}
+
 namespace chromeos {
 namespace options2 {
 
+// Operation class that encodes existing in-memory image as PNG.
+// It uses NO-COMPRESSION to save time.
+class WallpaperImageSource::WallpaperEncodingOperation
+    : public base::RefCountedThreadSafe<
+          WallpaperImageSource::WallpaperEncodingOperation> {
+ public:
+  WallpaperEncodingOperation(
+      int request_id,
+      scoped_refptr<base::RefCountedBytes> data,
+      SkBitmap image)
+      : request_id_(request_id),
+        data_(data),
+        image_(image) {
+  }
+
+  static void Run(scoped_refptr<WallpaperEncodingOperation> weo) {
+    weo->EncodeWallpaper();
+  }
+
+  int request_id() {
+    return request_id_;
+  }
+
+  void EncodeWallpaper() {
+    if (cancel_flag_.IsSet())
+      return;
+    TRACE_EVENT0("LOCK_SCREEN", "imageEncoding");
+    SkAutoLockPixels lock_input(image_);
+    // Avoid compression to make things faster.
+    gfx::PNGCodec::EncodeWithCompressionLevel(
+        reinterpret_cast<unsigned char*>(image_.getAddr32(0, 0)),
+        gfx::PNGCodec::FORMAT_SkBitmap,
+        gfx::Size(image_.width(), image_.height()),
+        image_.width() * image_.bytesPerPixel(),
+        false,
+        std::vector<gfx::PNGCodec::Comment>(),
+        Z_NO_COMPRESSION,
+        &data_->data());
+    if (cancel_flag_.IsSet())
+      return;
+  }
+
+  void Cancel() {
+    cancel_flag_.Set();
+  }
+
+ private:
+  friend class base::RefCountedThreadSafe<
+      WallpaperImageSource::WallpaperEncodingOperation>;
+
+  ~WallpaperEncodingOperation() {}
+
+  base::CancellationFlag cancel_flag_;
+
+  // ID of original request.
+  int request_id_;
+  // Buffer to store encoded image.
+  scoped_refptr<base::RefCountedBytes> data_;
+  // Original image to encode.
+  SkBitmap image_;
+
+  DISALLOW_COPY_AND_ASSIGN(WallpaperEncodingOperation);
+};
+
 WallpaperImageSource::WallpaperImageSource()
     : DataSource(chrome::kChromeUIWallpaperImageHost, NULL),
       weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
@@ -67,37 +143,31 @@
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
   CancelPendingEncodingOperation();
   scoped_refptr<base::RefCountedBytes> data = new base::RefCountedBytes();
-
-  png_encoder_ = new SimplePngEncoder(
-      data,
-      image,
-      base::Bind(&WallpaperImageSource::CancelCallback,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 request_id));
-
-  TRACE_EVENT0("LOCK_SCREEN", "imageEncoding");
-  png_encoder_->Run(
+  wallpaper_encoding_op_ = new WallpaperEncodingOperation(request_id,
+                                                          data,
+                                                          image);
+  base::WorkerPool::PostTaskAndReply(
+      FROM_HERE,
+      base::Bind(&WallpaperEncodingOperation::Run, wallpaper_encoding_op_),
       base::Bind(&WallpaperImageSource::SendCurrentUserWallpaper,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 request_id));
+                 weak_ptr_factory_.GetWeakPtr(), request_id, data),
+      true /* task_is_slow */);
 };
 
 void WallpaperImageSource::CancelPendingEncodingOperation() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
   // Set canceled flag of previous request to skip unneeded encoding.
-  if (png_encoder_.get()) {
-    png_encoder_->Cancel();
+  if (wallpaper_encoding_op_.get()) {
+    wallpaper_encoding_op_->Cancel();
+    SendResponse(wallpaper_encoding_op_->request_id(), NULL);
+    TRACE_EVENT_ASYNC_END0("SCREEN_LOCK", "GetUserWallpaper",
+                           wallpaper_encoding_op_->request_id());
   }
 
-  // Cancel the callback for the previous request.
+  // Cancel reply callback for previous request.
   weak_ptr_factory_.InvalidateWeakPtrs();
 }
 
-void WallpaperImageSource::CancelCallback(int request_id) {
-    SendResponse(request_id, NULL);
-    TRACE_EVENT_ASYNC_END0("SCREEN_LOCK", "GetUserWallpaper", request_id);
-}
-
 void WallpaperImageSource::SendCurrentUserWallpaper(int request_id,
     scoped_refptr<base::RefCountedBytes> data) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));