Bug 942736 - Account for hidden margins when validating viewport metrics. r=kats

mobile/android/base/gfx/JavaPanZoomController.java

@@ -1029,6 +1029,11 @@ class JavaPanZoomController
         float zoomFactor = viewportMetrics.zoomFactor;
         RectF pageRect = viewportMetrics.getPageRect();
         RectF viewport = viewportMetrics.getViewport();
+        RectF maxMargins = mTarget.getMaxMargins();
+        RectF margins = new RectF(Math.max(maxMargins.left, viewportMetrics.marginLeft),
+                                  Math.max(maxMargins.top, viewportMetrics.marginTop),
+                                  Math.max(maxMargins.right, viewportMetrics.marginRight),
+                                  Math.max(maxMargins.bottom, viewportMetrics.marginBottom));
 
         float focusX = viewport.width() / 2.0f;
         float focusY = viewport.height() / 2.0f;
@@ -1050,18 +1055,14 @@ class JavaPanZoomController
 
         // Ensure minZoomFactor keeps the page at least as big as the viewport.
         if (pageRect.width() > 0) {
-            float pageWidth = pageRect.width() +
-              viewportMetrics.marginLeft +
-              viewportMetrics.marginRight;
+            float pageWidth = pageRect.width() + margins.left + margins.right;
             float scaleFactor = viewport.width() / pageWidth;
             minZoomFactor = Math.max(minZoomFactor, zoomFactor * scaleFactor);
             if (viewport.width() > pageWidth)
                 focusX = 0.0f;
         }
         if (pageRect.height() > 0) {
-            float pageHeight = pageRect.height() +
-              viewportMetrics.marginTop +
-              viewportMetrics.marginBottom;
+            float pageHeight = pageRect.height() + margins.top + margins.bottom;
             float scaleFactor = viewport.height() / pageHeight;
             minZoomFactor = Math.max(minZoomFactor, zoomFactor * scaleFactor);
             if (viewport.height() > pageHeight)

mobile/android/base/gfx/LayerMarginsAnimator.java

@@ -93,7 +93,7 @@ public class LayerMarginsAnimator {
                 + ", \"bottom\" : " + bottom + ", \"left\" : " + left + " }"));
     }
 
-    RectF getMaxMargins() {
+    synchronized RectF getMaxMargins() {
         return mMaxMargins;
     }