Backing out changeset e1983b9db75d from bug 596955 for causing bug 615858. a=backout

widget/src/cocoa/nsCocoaWindow.h

@@ -281,6 +281,11 @@ public:
     // be notified that a some form of drag event needs to go into Gecko
     virtual PRBool DragEvent(unsigned int aMessage, Point aMouseGlobal, UInt16 aKeyModifiers);
 
+    // Helpers to prevent recursive resizing during live-resize
+    PRBool IsResizing () const { return mIsResizing; }
+    void StartResizing () { mIsResizing = PR_TRUE; }
+    void StopResizing () { mIsResizing = PR_FALSE; }
+
     PRBool HasModalDescendents() { return mNumModalDescendents > 0; }
     NSWindow *GetCocoaWindow() { return mWindow; }
 
@@ -333,6 +338,7 @@ protected:
   PRInt32              mShadowStyle;
   NSUInteger           mWindowFilter;
 
+  PRPackedBool         mIsResizing;     // we originated the resize, prevent infinite recursion
   PRPackedBool         mWindowMadeHere; // true if we created the window, false for embedding
   PRPackedBool         mSheetNeedsShow; // if this is a sheet, are we waiting to be shown?
                                         // this is used for sibling sheet contention only

widget/src/cocoa/nsCocoaWindow.mm

@@ -139,6 +139,7 @@ nsCocoaWindow::nsCocoaWindow()
 , mPopupContentView(nil)
 , mShadowStyle(NS_STYLE_WINDOW_SHADOW_DEFAULT)
 , mWindowFilter(0)
+, mIsResizing(PR_FALSE)
 , mWindowMadeHere(PR_FALSE)
 , mSheetNeedsShow(PR_FALSE)
 , mFullScreen(PR_FALSE)
@@ -1133,16 +1134,35 @@ NS_IMETHODIMP nsCocoaWindow::Resize(PRInt32 aX, PRInt32 aY, PRInt32 aWidth, PRIn
   BOOL isMoving = (windowBounds.x != newBounds.x || windowBounds.y != newBounds.y);
   BOOL isResizing = (windowBounds.width != newBounds.width || windowBounds.height != newBounds.height);
 
-  if (!mWindow || (!isMoving && !isResizing))
+  if (IsResizing() || !mWindow || (!isMoving && !isResizing))
     return NS_OK;
   
   mBounds = newBounds;
   NSRect newFrame = nsCocoaUtils::GeckoRectToCocoaRect(mBounds);
 
+  // We have to report the size event -first-, to make sure that content
+  // repositions itself.  Cocoa views are anchored at the bottom left,
+  // so if we don't do this our child view will end up being stuck in the
+  // wrong place during a resize.
+  if (isResizing)
+    ReportSizeEvent(&newFrame);
+
+  StartResizing();
   // We ignore aRepaint -- we have to call display:YES, otherwise the
   // title bar doesn't immediately get repainted and is displayed in
   // the wrong place, leading to a visual jump.
   [mWindow setFrame:newFrame display:YES];
+  StopResizing();
+
+  // now, check whether we got the frame that we wanted
+  NSRect actualFrame = [mWindow frame];
+  if (newFrame.size.width != actualFrame.size.width || newFrame.size.height != actualFrame.size.height) {
+    // We didn't; the window must have been too big or otherwise invalid.
+    // Report -another- resize in this case, to make sure things are in
+    // the right place.  This will cause some visual jitter, but
+    // shouldn't happen often.
+    ReportSizeEvent();
+  }
 
   return NS_OK;
 
@@ -1768,7 +1788,7 @@ PRBool nsCocoaWindow::ShouldFocusPlugin()
 
 - (void)windowDidResize:(NSNotification *)aNotification
 {
-  if (!mGeckoWindow)
+  if (!mGeckoWindow || mGeckoWindow->IsResizing())
     return;
 
   // Resizing might have changed our zoom state.