Changes to content/ to facilitate new zoom extension API

content/public/common/page_zoom.h

 // Copyright (c) 2012 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 CONTENT_PUBLIC_COMMON_PAGE_ZOOM_H_
 #define CONTENT_PUBLIC_COMMON_PAGE_ZOOM_H_
 
+#include <string>
+
+#include "base/logging.h"
+#include "base/values.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
 // This enum is the parameter to various text/page zoom commands so we know
 // what the specific zoom command is.
 enum PageZoom {
   PAGE_ZOOM_OUT   = -1,
   PAGE_ZOOM_RESET = 0,
   PAGE_ZOOM_IN    = 1,
@@ skipping 14 matching lines @@
 CONTENT_EXPORT extern const double kEpsilon;
 
 // Test if two zoom values (either zoom factors or zoom levels) should be
 // considered equal.
 CONTENT_EXPORT bool ZoomValuesEqual(double value_a, double value_b);
 
 // Converts between zoom factors and levels.
 CONTENT_EXPORT double ZoomLevelToZoomFactor(double zoom_level);
 CONTENT_EXPORT double ZoomFactorToZoomLevel(double factor);
 
+// Defines how zoom changes are handled.
+// |kZoomModeDefault| results in default zoom behavior, i.e. zoom changes are
+//     handled automatically and on a per-origin basis, meaning that other
+//     tabs navigated to the same origin will also zoom.
+// |kZoomModeIsolated| results in zoom changes being handled automatically,
+//     but on a per-tab basis. Tabs in this zoom mode will not be affected by
+//     zoom changes in other tabs, and vice versa.
+// |kZoomModeManual| overrides the automatic handling of zoom changes. The
+//     |onZoomChange| event will still be dispatched, but the page will not
+//     actually be zoomed. These zoom changes can be handled manually by
+//     listening for the |onZoomChange| event. Zooming in this mode is also on
+//     a per-tab basis.
+// |kZoomModeDisabled| disables all zooming in this tab. The tab will revert
+//     to default (100%) zoom, and all attempted zoom changes will be ignored.
+enum ZoomMode {
+  kZoomModeDefault,
+  kZoomModeIsolated,
+  kZoomModeManual,
+  kZoomModeDisabled,
+};
+
+// Details for the |onZoomChange| event.
+struct ZoomChangeDetails {
+  double old_zoom_level;
+  double new_zoom_level;
+  content::ZoomMode zoom_mode;
+};
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_PAGE_ZOOM_H_