Implement a status throbber on the mac, currently using the Win artwork. Made the tab cell use a generic NSView for showing the icon instead of relying on the NSButtonCell to draw it, so a NSImageView is in place by default. Remove un-needed outlets, bindings, and views from the nib. BUG=11916. TEST=loading pages, opening and closing tabs.

Review URL: http://codereview.chromium.org/115527

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@16410 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 327 insertions, 98 deletions

diff --git a/chrome/app/nibs/en.lproj/TabView.xib b/chrome/app/nibs/en.lproj/TabView.xib
index 3cd6798..9752f4b 100644
--- a/chrome/app/nibs/en.lproj/TabView.xib
+++ b/chrome/app/nibs/en.lproj/TabView.xib
@@ -2,10 +2,10 @@
 <archive type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="7.03">
 	<data>
 		<int key="IBDocument.SystemTarget">1050</int>
-		<string key="IBDocument.SystemVersion">9G55</string>
+		<string key="IBDocument.SystemVersion">9F33</string>
 		<string key="IBDocument.InterfaceBuilderVersion">677</string>
-		<string key="IBDocument.AppKitVersion">949.43</string>
-		<string key="IBDocument.HIToolboxVersion">353.00</string>
+		<string key="IBDocument.AppKitVersion">949.34</string>
+		<string key="IBDocument.HIToolboxVersion">352.00</string>
 		<object class="NSMutableArray" key="IBDocument.EditedObjectIDs">
 			<bool key="EncodedWithXMLCoder">YES</bool>
 			<integer value="1"/>
@@ -58,10 +58,6 @@
 							<reference key="NSControlView" ref="279592484"/>
 							<int key="NSButtonFlags">-2034482945</int>
 							<int key="NSButtonFlags2">134</int>
-							<object class="NSCustomResource" key="NSNormalImage">
-								<string key="NSClassName">NSImage</string>
-								<string key="NSResourceName">nav</string>
-							</object>
 							<string key="NSAlternateContents"/>
 							<string key="NSKeyEquivalent"/>
 							<int key="NSPeriodicDelay">400</int>
@@ -100,15 +96,37 @@
 						</object>
 						<bool key="NSEditable">YES</bool>
 					</object>
-					<object class="NSProgressIndicator" id="58797509">
+					<object class="NSImageView" id="987403091">
 						<reference key="NSNextResponder" ref="1005"/>
-						<int key="NSvFlags">-2147482327</int>
-						<object class="NSPSMatrix" key="NSDrawMatrix"/>
-						<string key="NSFrame">{{131, 4}, {16, 16}}</string>
+						<int key="NSvFlags">268</int>
+						<object class="NSMutableSet" key="NSDragTypes">
+							<bool key="EncodedWithXMLCoder">YES</bool>
+							<object class="NSMutableArray" key="set.sortedObjects">
+								<bool key="EncodedWithXMLCoder">YES</bool>
+								<string>Apple PDF pasteboard type</string>
+								<string>Apple PICT pasteboard type</string>
+								<string>Apple PNG pasteboard type</string>
+								<string>NSFilenamesPboardType</string>
+								<string>NeXT Encapsulated PostScript v1.2 pasteboard type</string>
+								<string>NeXT TIFF v4.0 pasteboard type</string>
+							</object>
+						</object>
+						<string key="NSFrame">{{18, 5}, {16, 16}}</string>
 						<reference key="NSSuperview" ref="1005"/>
-						<int key="NSpiFlags">28938</int>
-						<double key="NSMinValue">1.600000e+01</double>
-						<double key="NSMaxValue">1.000000e+02</double>
+						<bool key="NSEnabled">YES</bool>
+						<object class="NSImageCell" key="NSCell" id="1061639670">
+							<int key="NSCellFlags">537001472</int>
+							<int key="NSCellFlags2">33587200</int>
+							<object class="NSCustomResource" key="NSContents">
+								<string key="NSClassName">NSImage</string>
+								<string key="NSResourceName">nav</string>
+							</object>
+							<int key="NSAlign">0</int>
+							<int key="NSScale">2</int>
+							<int key="NSStyle">0</int>
+							<bool key="NSAnimates">NO</bool>
+						</object>
+						<bool key="NSEditable">YES</bool>
 					</object>
 					<object class="NSButton" id="1054640993">
 						<reference key="NSNextResponder" ref="1005"/>
@@ -160,14 +178,6 @@
 					<int key="connectionID">25</int>
 				</object>
 				<object class="IBConnectionRecord">
-					<object class="IBOutletConnection" key="connection">
-						<string key="label">progressIndicator_</string>
-						<reference key="source" ref="1001"/>
-						<reference key="destination" ref="58797509"/>
-					</object>
-					<int key="connectionID">27</int>
-				</object>
-				<object class="IBConnectionRecord">
 					<object class="IBBindingConnection" key="connection">
 						<string key="label">title: title</string>
 						<reference key="source" ref="707804163"/>
@@ -185,58 +195,6 @@
 				</object>
 				<object class="IBConnectionRecord">
 					<object class="IBBindingConnection" key="connection">
-						<string key="label">animate: loading</string>
-						<reference key="source" ref="58797509"/>
-						<reference key="destination" ref="1001"/>
-						<object class="NSNibBindingConnector" key="connector">
-							<reference key="NSSource" ref="58797509"/>
-							<reference key="NSDestination" ref="1001"/>
-							<string key="NSLabel">animate: loading</string>
-							<string key="NSBinding">animate</string>
-							<string key="NSKeyPath">loading</string>
-							<int key="NSNibBindingConnectorVersion">2</int>
-						</object>
-					</object>
-					<int key="connectionID">31</int>
-				</object>
-				<object class="IBConnectionRecord">
-					<object class="IBBindingConnection" key="connection">
-						<string key="label">hidden: loading</string>
-						<reference key="source" ref="58797509"/>
-						<reference key="destination" ref="1001"/>
-						<object class="NSNibBindingConnector" key="connector">
-							<reference key="NSSource" ref="58797509"/>
-							<reference key="NSDestination" ref="1001"/>
-							<string key="NSLabel">hidden: loading</string>
-							<string key="NSBinding">hidden</string>
-							<string key="NSKeyPath">loading</string>
-							<object class="NSDictionary" key="NSOptions">
-								<string key="NS.key.0">NSValueTransformerName</string>
-								<string key="NS.object.0">NSNegateBoolean</string>
-							</object>
-							<int key="NSNibBindingConnectorVersion">2</int>
-						</object>
-					</object>
-					<int key="connectionID">43</int>
-				</object>
-				<object class="IBConnectionRecord">
-					<object class="IBBindingConnection" key="connection">
-						<string key="label">image: image</string>
-						<reference key="source" ref="279592484"/>
-						<reference key="destination" ref="1001"/>
-						<object class="NSNibBindingConnector" key="connector" id="703997475">
-							<reference key="NSSource" ref="279592484"/>
-							<reference key="NSDestination" ref="1001"/>
-							<string key="NSLabel">image: image</string>
-							<string key="NSBinding">image</string>
-							<string key="NSKeyPath">image</string>
-							<int key="NSNibBindingConnectorVersion">2</int>
-						</object>
-					</object>
-					<int key="connectionID">44</int>
-				</object>
-				<object class="IBConnectionRecord">
-					<object class="IBBindingConnection" key="connection">
 						<string key="label">title: title</string>
 						<reference key="source" ref="279592484"/>
 						<reference key="destination" ref="1001"/>
@@ -246,7 +204,7 @@
 							<string key="NSLabel">title: title</string>
 							<string key="NSBinding">title</string>
 							<string key="NSKeyPath">title</string>
-							<reference key="NSPreviousConnector" ref="703997475"/>
+							<reference key="NSPreviousConnector"/>
 							<int key="NSNibBindingConnectorVersion">2</int>
 						</object>
 					</object>
@@ -284,6 +242,14 @@
 					</object>
 					<int key="connectionID">54</int>
 				</object>
+				<object class="IBConnectionRecord">
+					<object class="IBOutletConnection" key="connection">
+						<string key="label">iconView_</string>
+						<reference key="source" ref="1001"/>
+						<reference key="destination" ref="987403091"/>
+					</object>
+					<int key="connectionID">58</int>
+				</object>
 			</object>
 			<object class="IBMutableOrderedSet" key="objectRecords">
 				<object class="NSArray" key="orderedObjects">
@@ -320,9 +286,9 @@
 						<object class="NSMutableArray" key="children">
 							<bool key="EncodedWithXMLCoder">YES</bool>
 							<reference ref="569334633"/>
-							<reference ref="58797509"/>
 							<reference ref="279592484"/>
 							<reference ref="1054640993"/>
+							<reference ref="987403091"/>
 						</object>
 						<reference key="parent" ref="1002"/>
 					</object>
@@ -341,11 +307,6 @@
 						<reference key="parent" ref="569334633"/>
 					</object>
 					<object class="IBObjectRecord">
-						<int key="objectID">12</int>
-						<reference key="object" ref="58797509"/>
-						<reference key="parent" ref="1005"/>
-					</object>
-					<object class="IBObjectRecord">
 						<int key="objectID">17</int>
 						<reference key="object" ref="279592484"/>
 						<object class="NSMutableArray" key="children">
@@ -373,6 +334,20 @@
 						<reference key="object" ref="348599947"/>
 						<reference key="parent" ref="1054640993"/>
 					</object>
+					<object class="IBObjectRecord">
+						<int key="objectID">55</int>
+						<reference key="object" ref="987403091"/>
+						<object class="NSMutableArray" key="children">
+							<bool key="EncodedWithXMLCoder">YES</bool>
+							<reference ref="1061639670"/>
+						</object>
+						<reference key="parent" ref="1005"/>
+					</object>
+					<object class="IBObjectRecord">
+						<int key="objectID">56</int>
+						<reference key="object" ref="1061639670"/>
+						<reference key="parent" ref="987403091"/>
+					</object>
 				</object>
 			</object>
 			<object class="NSMutableDictionary" key="flattenedProperties">
@@ -387,13 +362,14 @@
 					<string>1.IBViewEditorWindowController.showingLayoutRectangles</string>
 					<string>1.WindowOrigin</string>
 					<string>1.editorWindowContentRectSynchronizationRect</string>
-					<string>12.IBPluginDependency</string>
 					<string>17.IBEditorWindowLastContentRect</string>
 					<string>17.IBPluginDependency</string>
 					<string>18.CustomClassName</string>
 					<string>18.IBPluginDependency</string>
 					<string>50.IBPluginDependency</string>
 					<string>51.IBPluginDependency</string>
+					<string>55.IBPluginDependency</string>
+					<string>56.IBPluginDependency</string>
 				</object>
 				<object class="NSMutableArray" key="dict.values">
 					<bool key="EncodedWithXMLCoder">YES</bool>
@@ -405,13 +381,14 @@
 					<boolean value="NO"/>
 					<string>{628, 654}</string>
 					<string>{{217, 442}, {480, 272}}</string>
-					<string>com.apple.InterfaceBuilder.CocoaPlugin</string>
 					<string>{{77, 725}, {134, 29}}</string>
 					<string>com.apple.InterfaceBuilder.CocoaPlugin</string>
 					<string>TabCell</string>
 					<string>com.apple.InterfaceBuilder.CocoaPlugin</string>
 					<string>com.apple.InterfaceBuilder.CocoaPlugin</string>
 					<string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+					<string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+					<string>com.apple.InterfaceBuilder.CocoaPlugin</string>
 				</object>
 			</object>
 			<object class="NSMutableDictionary" key="unlocalizedProperties">
@@ -434,7 +411,7 @@
 				</object>
 			</object>
 			<nil key="sourceID"/>
-			<int key="maxID">54</int>
+			<int key="maxID">58</int>
 		</object>
 		<object class="IBClassDescriber" key="IBDocument.Classes">
 			<object class="NSMutableArray" key="referencedPartialClassDescriptions">
@@ -466,12 +443,14 @@
 						<object class="NSMutableArray" key="dict.sortedKeys">
 							<bool key="EncodedWithXMLCoder">YES</bool>
 							<string>backgroundButton_</string>
+							<string>iconView_</string>
 							<string>progressIndicator_</string>
 							<string>target_</string>
 						</object>
 						<object class="NSMutableArray" key="dict.values">
 							<bool key="EncodedWithXMLCoder">YES</bool>
 							<string>NSButton</string>
+							<string>NSView</string>
 							<string>NSProgressIndicator</string>
 							<string>id</string>
 						</object>
diff --git a/chrome/browser/cocoa/tab_cell.h b/chrome/browser/cocoa/tab_cell.h
index a3ad120..0f0ff0f 100644
--- a/chrome/browser/cocoa/tab_cell.h
+++ b/chrome/browser/cocoa/tab_cell.h
@@ -7,8 +7,11 @@
 
 #import <Cocoa/Cocoa.h>
 
-// A button cell that handles drawing/highlighting of tabs in the
-// tab bar.
+// A button cell that handles drawing/highlighting of tabs in the tab bar. Text
+// drawing leaves room for an icon view on the left of the tab and a close
+// button on the right. Technically, though, it doesn't know anything about what
+// it's leaving space for, so they could be reversed or even replaced by views
+// for other purposes.
 
 @interface TabCell : NSButtonCell {
 }
diff --git a/chrome/browser/cocoa/tab_cell.mm b/chrome/browser/cocoa/tab_cell.mm
index 205c7a5..a2adf27 100644
--- a/chrome/browser/cocoa/tab_cell.mm
+++ b/chrome/browser/cocoa/tab_cell.mm
@@ -145,11 +145,14 @@ namespace {
 
   [[NSGraphicsContext currentContext] restoreGraphicsState];
 
-  // Inset where the text and favicon are drawn to keep them away from the
-  // sloping edges of the tab and the close box.
-  int kInteriorInset = cellFrame.size.height / 2.0;
-  NSRect frame = NSInsetRect(cellFrame, kInteriorInset, 0);
-  frame.size.width -= 16; // Inset for close box
+  // Inset where the text is drawn to keep it away from the sloping edges of the
+  // tab, the close box, and the icon view. These constants are derived
+  // empirically as the cell doesn't know about the surrounding view objects.
+  // TODO(pinkerton/alcor): Fix this somehow?
+  const int kIconXOffset = 28;
+  const int kCloseBoxXOffset = 16;
+  NSRect frame = NSOffsetRect(cellFrame, kIconXOffset, 0);
+  frame.size.width -= kCloseBoxXOffset + kIconXOffset;
   [self drawInteriorWithFrame:frame
                        inView:controlView];
 }
diff --git a/chrome/browser/cocoa/tab_controller.h b/chrome/browser/cocoa/tab_controller.h
index 45d93ab..d7783b7 100644
--- a/chrome/browser/cocoa/tab_controller.h
+++ b/chrome/browser/cocoa/tab_controller.h
@@ -14,21 +14,33 @@
 // to be sent a message when the tab is selected by the user clicking. Setting
 // the |loading| property to YES visually indicates that this tab is currently
 // loading content via a spinner.
+//
+// The tab has the notion of an "icon view" which can be used to display
+// identifying characteristics such as a favicon, or since it's a full-fledged
+// view, something with state and animation such as a throbber for illustrating
+// progress. The default in the nib is an image view so nothing special is
+// required if that's all you need.
 
 @interface TabController : NSViewController {
  @private
   IBOutlet NSButton *backgroundButton_;
-  IBOutlet NSProgressIndicator *progressIndicator_;
+  IBOutlet NSView* iconView_;
   BOOL selected_;
   BOOL loading_;
-  NSImage *image_;
+  BOOL waiting_;
   id<TabControllerTarget> target_;  // weak, where actions are sent
   SEL action_;  // selector sent when tab is selected by clicking
 }
 
-@property(retain, nonatomic) NSImage *image;
-@property(assign, nonatomic) BOOL selected;
+// The loading/waiting state of the tab.
+// TODO(pinkerton): these really don't belong here, but something needs to
+// know the state and another parallel array in TabStripController doesn't seem
+// like the right place either. In a perfect world, this class shouldn't know
+// anything about states that are specific to a browser.
 @property(assign, nonatomic) BOOL loading;
+@property(assign, nonatomic) BOOL waiting;
+
+@property(assign, nonatomic) BOOL selected;
 @property(assign, nonatomic) id target;
 @property(assign, nonatomic) SEL action;
 
@@ -43,6 +55,11 @@
 // perform the close.
 - (IBAction)closeTab:(id)sender;
 
+// Replace the current icon view with the given view. |iconView| will be
+// resized to the size of the current icon view.
+- (void)setIconView:(NSView*)iconView;
+- (NSView*)iconView;
+
 @end
 
 #endif  // CHROME_BROWSER_COCOA_TAB_CONTROLLER_H_
diff --git a/chrome/browser/cocoa/tab_controller.mm b/chrome/browser/cocoa/tab_controller.mm
index 027f709..c5aae1a 100644
--- a/chrome/browser/cocoa/tab_controller.mm
+++ b/chrome/browser/cocoa/tab_controller.mm
@@ -8,8 +8,8 @@
 
 @implementation TabController
 
-@synthesize image = image_;
 @synthesize loading = loading_;
+@synthesize waiting = waiting_;
 @synthesize target = target_;
 @synthesize action = action_;
 
@@ -23,13 +23,11 @@
 - (id)init {
   self = [super initWithNibName:@"TabView" bundle:mac_util::MainAppBundle()];
   if (self != nil) {
-    [self setImage:[NSImage imageNamed:@"nav"]];
   }
   return self;
 }
 
 - (void)dealloc {
-  [image_ release];
   [super dealloc];
 }
 
@@ -44,6 +42,7 @@
 
 // Called when the tab's nib is done loading and all outlets are hooked up.
 - (void)awakeFromNib {
+  [(id)iconView_ setImage:[NSImage imageNamed:@"nav"]];
   [[self view] addSubview:backgroundButton_
                positioned:NSWindowBelow
                relativeTo:nil];
@@ -66,4 +65,16 @@
   return selected_;
 }
 
+- (void)setIconView:(NSView*)iconView {
+  NSRect currentFrame = [iconView_ frame];
+  [iconView_ removeFromSuperview];
+  iconView_ = iconView;
+  [iconView_ setFrame:currentFrame];
+  [[self view] addSubview:iconView_];
+}
+
+- (NSView*)iconView {
+  return iconView_;
+}
+
 @end
diff --git a/chrome/browser/cocoa/tab_strip_controller.mm b/chrome/browser/cocoa/tab_strip_controller.mm
index bbc18f0..2bbdec8 100644
--- a/chrome/browser/cocoa/tab_strip_controller.mm
+++ b/chrome/browser/cocoa/tab_strip_controller.mm
@@ -16,6 +16,7 @@
 #import "chrome/browser/cocoa/tab_controller.h"
 #import "chrome/browser/cocoa/tab_strip_model_observer_bridge.h"
 #import "chrome/browser/cocoa/tab_view.h"
+#import "chrome/browser/cocoa/throbber_view.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/tab_contents/tab_contents_view.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
@@ -357,6 +358,18 @@
   [self layoutTabs];
 }
 
+// A helper routine for creating an NSImageView to hold the fav icon for
+// |contents|.
+// TODO(pinkerton): fill in with code to use the real favicon, not the default
+// for all cases.
+- (NSImageView*)favIconImageViewForContents:(TabContents*)contents {
+  NSRect iconFrame = NSMakeRect(0, 0, 16, 16);
+  NSImageView* view = [[[NSImageView alloc] initWithFrame:iconFrame]
+                          autorelease];
+  [view setImage:[NSImage imageNamed:@"nav"]];
+  return view;
+}
+
 // Called when a notification is received from the model that the given tab
 // has been updated. |loading| will be YES when we only want to update the
 // throbber state, not anything else about the (partially) loading tab.
@@ -366,6 +379,35 @@
   if (!loading)
     [self setTabTitle:[tabArray_ objectAtIndex:index] withContents:contents];
 
+  // Update the current loading state, replacing the icon with a throbber, or
+  // vice versa. This will get called repeatedly with the same state during a
+  // load, so we need to make sure we're not creating the throbber view over and
+  // over.
+  if (contents) {
+    TabController* tabController = [tabArray_ objectAtIndex:index];
+    NSString* imageName = nil;
+    if (contents->waiting_for_response() && ![tabController waiting]) {
+      imageName = @"throbber_waiting";
+      [tabController setWaiting:YES];
+    } else if (contents->is_loading() && ![tabController loading]) {
+      imageName = @"throbber";
+      [tabController setLoading:YES];
+    }
+    if (imageName) {
+      NSRect frame = NSMakeRect(0, 0, 16, 16);
+      NSImage* image = [NSImage imageNamed:imageName];
+      ThrobberView* throbber =
+          [[[ThrobberView alloc] initWithFrame:frame image:image] autorelease];
+      [tabController setIconView:throbber];
+    }
+    else if (!contents->is_loading()) {
+      // Set everything back to normal, we're done loading.
+      [tabController setIconView:[self favIconImageViewForContents:contents]];
+      [tabController setWaiting:NO];
+      [tabController setLoading:NO];
+    }
+  }
+
   TabContentsController* updatedController =
       [tabContentsArray_ objectAtIndex:index];
   [updatedController tabDidChange:contents];
diff --git a/chrome/browser/cocoa/throbber_view.h b/chrome/browser/cocoa/throbber_view.h
new file mode 100644
index 0000000..5403371
--- /dev/null
+++ b/chrome/browser/cocoa/throbber_view.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_COCOA_THROBBER_VIEW_H_
+#define CHROME_BROWSER_COCOA_THROBBER_VIEW_H_
+
+#import <Cocoa/Cocoa.h>
+
+#include "base/scoped_nsobject.h"
+
+@class TimerTarget;
+
+// A class that knows how to draw an animated state to indicate progress.
+// Currently draws via a sequence of frames in an image, but may ultimately be
+// written to render paths that are rotated around a center origin. Creating
+// the class starts the animation, destroying it stops it. There is no state
+// where the class is frozen on an image and not animating.
+
+@interface ThrobberView : NSView {
+ @private
+  scoped_nsobject<NSImage> image_;
+  scoped_nsobject<TimerTarget> target_;  // Target of animation timer.
+  NSTimer* timer_;  // Animation timer. Weak, owned by runloop.
+  unsigned int numFrames_;  // Number of frames in this animation.
+  unsigned int animationFrame_;  // Current frame of the animation,
+                                 // [0..numFrames_)
+}
+
+// Creates the view with |frame| and the image strip desginated by |image|. The
+// image needs to be made of squares such that the height divides evently into
+// the width. Takes ownership of |image|.
+- (id)initWithFrame:(NSRect)frame image:(NSImage*)image;
+
+@end
+
+#endif  // CHROME_BROWSER_COCOA_THROBBER_VIEW_H_
diff --git a/chrome/browser/cocoa/throbber_view.mm b/chrome/browser/cocoa/throbber_view.mm
new file mode 100644
index 0000000..948dcb4
--- /dev/null
+++ b/chrome/browser/cocoa/throbber_view.mm
@@ -0,0 +1,88 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "chrome/browser/cocoa/throbber_view.h"
+
+#include "base/logging.h"
+
+const float kAnimationIntervalSeconds = 0.03;  // 30ms, same as windows
+
+@interface ThrobberView(PrivateMethods)
+- (void)animate;
+@end
+
+// A very simple object that is the target for the animation timer so that
+// the view isn't. We do this to avoid retain cycles as the timer
+// retains its target.
+@interface TimerTarget : NSObject {
+ @private
+  ThrobberView* throbber_;  // Weak, owns us
+}
+- (id)initWithThrobber:(ThrobberView*)view;
+@end
+
+@implementation TimerTarget
+- (id)initWithThrobber:(ThrobberView*)view {
+  if ((self = [super init])) {
+    throbber_ = view;
+  }
+  return self;
+}
+
+- (void)animate:(NSTimer*)timer {
+  [throbber_ animate];
+}
+@end
+
+@implementation ThrobberView
+
+- (id)initWithFrame:(NSRect)frame image:(NSImage*)image {
+  if ((self = [super initWithFrame:frame])) {
+    // Ensure that the height divides evenly into the width. Cache the
+    // number of frames in the animation for later.
+    NSSize imageSize = [image size];
+    DCHECK(imageSize.height && imageSize.width);
+    if (!imageSize.height)
+      return nil;
+    DCHECK((int)imageSize.width % (int)imageSize.height == 0);
+    numFrames_ = (int)imageSize.width / (int)imageSize.height;
+    DCHECK(numFrames_);
+    image_.reset([image retain]);
+
+    // Start a timer for the animation frames.
+    target_.reset([[TimerTarget alloc] initWithThrobber:self]);
+    timer_ =
+        [NSTimer scheduledTimerWithTimeInterval:kAnimationIntervalSeconds
+                                         target:target_.get()
+                                       selector:@selector(animate:)
+                                       userInfo:nil
+                                        repeats:YES];
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [timer_ invalidate];
+  [super dealloc];
+}
+
+// Called when the TimerTarget gets tickled by our timer. Increment the frame
+// counter and mark as needing display.
+- (void)animate {
+  animationFrame_ = ++animationFrame_ % numFrames_;
+  [self setNeedsDisplay:YES];
+}
+
+// Overridden to draw the appropriate frame in the image strip.
+- (void)drawRect:(NSRect)rect {
+  float imageDimension = [image_ size].height;
+  float xOffset = animationFrame_ * imageDimension;
+  NSRect sourceImageRect =
+      NSMakeRect(xOffset, 0, imageDimension, imageDimension);
+  [image_ compositeToPoint:NSMakePoint(0, 0)
+                  fromRect:sourceImageRect
+                 operation:NSCompositeSourceOver];
+}
+
+@end
diff --git a/chrome/browser/cocoa/throbber_view_unittest.mm b/chrome/browser/cocoa/throbber_view_unittest.mm
new file mode 100644
index 0000000..72d2240
--- /dev/null
+++ b/chrome/browser/cocoa/throbber_view_unittest.mm
@@ -0,0 +1,44 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <Cocoa/Cocoa.h>
+
+#include "base/scoped_nsobject.h"
+#import "chrome/browser/cocoa/throbber_view.h"
+#import "chrome/browser/cocoa/cocoa_test_helper.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/platform_test.h"
+
+namespace {
+
+class ThrobberViewTest : public PlatformTest {
+ public:
+  ThrobberViewTest() {
+    NSRect frame = NSMakeRect(10, 10, 16, 16);
+    NSBundle* bundle = mac_util::MainAppBundle();
+    NSImage* image = [[[NSImage alloc] initByReferencingFile:
+                        [bundle pathForResource:@"throbber" ofType:@"png"]]
+                        autorelease];
+    view_.reset([[ThrobberView alloc] initWithFrame:frame image:image]);
+    [cocoa_helper_.contentView() addSubview:view_.get()];
+  }
+
+  scoped_nsobject<ThrobberView> view_;
+  CocoaTestHelper cocoa_helper_;  // Inits Cocoa, creates window, etc...
+};
+
+// Test adding/removing from the view hierarchy, mostly to ensure nothing
+// leaks or crashes.
+TEST_F(ThrobberViewTest, AddRemove) {
+  EXPECT_EQ(cocoa_helper_.contentView(), [view_ superview]);
+  [view_.get() removeFromSuperview];
+  EXPECT_FALSE([view_ superview]);
+}
+
+// Test drawing, mostly to ensure nothing leaks or crashes.
+TEST_F(ThrobberViewTest, Display) {
+  [view_ display];
+}
+
+}  // namespace
diff --git a/chrome/chrome.gyp b/chrome/chrome.gyp
index 83d5766..6155d2f 100644
--- a/chrome/chrome.gyp
+++ b/chrome/chrome.gyp
@@ -671,6 +671,8 @@
         'browser/cocoa/tab_view.mm',
         'browser/cocoa/tab_window_controller.h',
         'browser/cocoa/tab_window_controller.mm',
+        'browser/cocoa/throbber_view.h',
+        'browser/cocoa/throbber_view.mm',
         'browser/cocoa/toolbar_button_cell.h',
         'browser/cocoa/toolbar_button_cell.mm',
         'browser/cocoa/toolbar_controller.h',
@@ -1933,6 +1935,8 @@
         'app/theme/star.pdf',
         'app/theme/starred.pdf',
         'app/theme/stop.pdf',
+        'app/theme/throbber.png',
+        'app/theme/throbber_waiting.png',
         'app/app-Info.plist',
       ],
       # TODO(mark): Come up with a fancier way to do this.  It should only
@@ -2711,6 +2715,7 @@
         'browser/cocoa/tab_strip_controller_unittest.mm',
         'browser/cocoa/tab_strip_view_unittest.mm',
         'browser/cocoa/tab_view_unittest.mm',
+        'browser/cocoa/throbber_view_unittest.mm',
         'browser/cocoa/toolbar_button_cell_unittest.mm',
         'browser/cocoa/toolbar_controller_unittest.mm',
         'browser/cocoa/toolbar_view_unittest.mm',