aura: Put pinch-to-zoom behind a flag (--enable-pinch or --enable-viewport)

content/browser/renderer_host/render_widget_host_view_aura.cc

 // 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.
 
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
 #include "content/browser/renderer_host/backing_store_skia.h"
 #include "content/browser/renderer_host/image_transport_client.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/web_input_event_aura.h"
 #include "content/common/gpu/client/gl_helper.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/port/browser/render_widget_host_view_port.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/common/content_switches.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCompositionUnderline.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebScreenInfo.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/tooltip_client.h"
 #include "ui/aura/client/window_types.h"
 #include "ui/aura/env.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
@@ skipping 83 matching lines @@
   results->rect = WebKit::WebRect(0, 0, size.width(), size.height());
   results->availableRect = results->rect;
   // TODO(derat|oshima): Don't hardcode this. Get this from monitor object.
   results->depth = 24;
   results->depthPerComponent = 8;
   int default_dpi = monitor.device_scale_factor() * 160;
   results->verticalDPI = default_dpi;
   results->horizontalDPI = default_dpi;
 }
 
+bool ShouldSendPinchGesture() {
+  static bool pinch_allowed =
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableViewport) ||
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnablePinch);
+  return pinch_allowed;
+}
+
 }  // namespace
 
 // We have to implement the WindowObserver interface on a separate object
 // because clang doesn't like implementing multiple interfaces that have
 // methods with the same name. This object is owned by the
 // RenderWidgetHostViewAura.
 class RenderWidgetHostViewAura::WindowObserver : public aura::WindowObserver {
  public:
   WindowObserver(RenderWidgetHostViewAura* view) : view_(view) {}
   virtual ~WindowObserver() {}
@@ skipping 923 matching lines @@
     host_->ForwardTouchEvent(touch_event_);
     UpdateWebTouchEventAfterDispatch(&touch_event_, point);
     return DecideTouchStatus(touch_event_, point);
   }
 
   return ui::TOUCH_STATUS_UNKNOWN;
 }
 
 ui::GestureStatus RenderWidgetHostViewAura::OnGestureEvent(
     aura::GestureEvent* event) {
+  // Pinch gestures are currently disabled by default. See crbug.com/128477.
+  if ((event->type() == ui::ET_GESTURE_PINCH_BEGIN ||
+      event->type() == ui::ET_GESTURE_PINCH_UPDATE ||
+      event->type() == ui::ET_GESTURE_PINCH_END) && !ShouldSendPinchGesture()) {
+    return ui::GESTURE_STATUS_CONSUMED;
+  }
+
   WebKit::WebGestureEvent gesture = content::MakeWebGestureEvent(event);
   if (event->type() == ui::ET_GESTURE_TAP_DOWN) {
     // Webkit does not stop a fling-scroll on tap-down. So explicitly send an
     // event to stop any in-progress flings.
     WebKit::WebGestureEvent fling_cancel = gesture;
     fling_cancel.type = WebKit::WebInputEvent::GestureFlingCancel;
     host_->ForwardGestureEvent(fling_cancel);
   }
   host_->ForwardGestureEvent(gesture);
 
@@ skipping 216 matching lines @@
 RenderWidgetHostView* RenderWidgetHostView::CreateViewForWidget(
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void content::RenderWidgetHostViewPort::GetDefaultScreenInfo(
     WebKit::WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }