Eliminate all UI thread decoding of extension images.

Except one, that is. We have one location we need to 
take a look at (I've added a comment). This changelist 
converts UI usage of DecodeImage on the UI thread to 
a revamped and simplified ImageLoadingTracker class. 

I plan on adding to GetFilePath a DCHECK for the File 
thread but decided to do so in another changelist, 
since it has a high likelyhood of flushing something 
out and be backed out because of that. This started 
out as issue 38521 (make infobar use cached icons) 
but grew in scope to just eliminate all UI thread 
access to DecodeImage and GetFilePath. 

BUG=http://crbug.com/38521 
TEST=None (extensions should work as before)

Review URL: http://codereview.chromium.org/1075006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@42471 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 9 insertions, 14 deletions

diff --git a/chrome/browser/views/browser_actions_container.cc b/chrome/browser/views/browser_actions_container.cc
index 0f3eff7..088b0ed 100644
--- a/chrome/browser/views/browser_actions_container.cc
+++ b/chrome/browser/views/browser_actions_container.cc
@@ -98,7 +98,7 @@ BrowserActionButton::BrowserActionButton(Extension* extension,
     : ALLOW_THIS_IN_INITIALIZER_LIST(MenuButton(this, L"", NULL, false)),
       browser_action_(extension->browser_action()),
       extension_(extension),
-      tracker_(NULL),
+      ALLOW_THIS_IN_INITIALIZER_LIST(tracker_(this)),
       showing_context_menu_(false),
       panel_(panel) {
   set_alignment(TextButton::ALIGN_CENTER);
@@ -120,16 +120,12 @@ BrowserActionButton::BrowserActionButton(Extension* extension,
   // will crash. But since we know that ImageLoadingTracker is asynchronous,
   // this should be OK. And doing this in the constructor means that we don't
   // have to protect against it getting done multiple times.
-  tracker_ = new ImageLoadingTracker(this, 1);
-  tracker_->PostLoadImageTask(
-      extension->GetResource(relative_path),
-      gfx::Size(Extension::kBrowserActionIconMaxSize,
-                Extension::kBrowserActionIconMaxSize));
+  tracker_.LoadImage(extension->GetResource(relative_path),
+                     gfx::Size(Extension::kBrowserActionIconMaxSize,
+                               Extension::kBrowserActionIconMaxSize));
 }
 
 BrowserActionButton::~BrowserActionButton() {
-  if (tracker_)
-    tracker_->StopTrackingImageLoad();
 }
 
 gfx::Insets BrowserActionButton::GetInsets() const {
@@ -142,12 +138,11 @@ void BrowserActionButton::ButtonPressed(views::Button* sender,
   panel_->OnBrowserActionExecuted(this, false);  // inspect_with_devtools
 }
 
-void BrowserActionButton::OnImageLoaded(SkBitmap* image, size_t index) {
+void BrowserActionButton::OnImageLoaded(
+    SkBitmap* image, ExtensionResource resource, int index) {
   if (image)
     default_icon_ = *image;
 
-  tracker_ = NULL;  // The tracker object will delete itself when we return.
-
   // Call back to UpdateState() because a more specific icon might have been set
   // while the load was outstanding.
   UpdateState();
@@ -207,7 +202,7 @@ GURL BrowserActionButton::GetPopupUrl() {
 
 bool BrowserActionButton::Activate() {
   if (IsPopup()) {
-    panel_->OnBrowserActionExecuted(this, false); // inspect_with_devtools
+    panel_->OnBrowserActionExecuted(this, false);  // |inspect_with_devtools|.
 
     // TODO(erikkay): Run a nested modal loop while the mouse is down to
     // enable menu-like drag-select behavior.
@@ -511,7 +506,7 @@ void BrowserActionsContainer::HidePopup() {
 
 void BrowserActionsContainer::TestExecuteBrowserAction(int index) {
   BrowserActionButton* button = browser_action_views_[index]->button();
-  OnBrowserActionExecuted(button, false); // inspect_with_devtools
+  OnBrowserActionExecuted(button, false);  // |inspect_with_devtools|.
 }
 
 void BrowserActionsContainer::TestSetIconVisibilityCount(size_t icons) {
@@ -1114,7 +1109,7 @@ void BrowserActionsContainer::NotifyMenuDeleted(
 void BrowserActionsContainer::InspectPopup(
     ExtensionAction* action) {
   OnBrowserActionExecuted(GetBrowserActionView(action)->button(),
-      true); // inspect_with_devtools
+      true);  // |inspect_with_devtools|.
 }
 
 void BrowserActionsContainer::ExtensionPopupClosed(ExtensionPopup* popup) {