Make WebView work for external displays (over Presentations).

ui/android/screen_android.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 "ui/gfx/screen.h"
 
 #include "base/logging.h"
+#include "ui/android/view_android.h"
+#include "ui/android/window_android.h"
 #include "ui/gfx/android/device_display_info.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/geometry/size_conversions.h"
 
 namespace gfx {
 
+gfx::Display DisplayFromDeviceDisplayInfo(
+    const gfx::DeviceDisplayInfo & device_info) {
+  const float device_scale_factor = device_info.GetDIPScale();
+  // Note: GetPhysicalDisplayWidth/Height() does not subtract window
+  // decorations etc. Use it instead of GetDisplayWidth/Height() when
+  // available.
+  const gfx::Rect bounds_in_pixels =
+      gfx::Rect(device_info.GetPhysicalDisplayWidth()
+                    ? device_info.GetPhysicalDisplayWidth()
+                    : device_info.GetDisplayWidth(),
+                device_info.GetPhysicalDisplayHeight()
+                    ? device_info.GetPhysicalDisplayHeight()
+                    : device_info.GetDisplayHeight());
+  const gfx::Rect bounds_in_dip =
+      gfx::Rect(gfx::ToCeiledSize(gfx::ScaleSize(
+          bounds_in_pixels.size(), 1.0f / device_scale_factor)));
+  gfx::Display display(0, bounds_in_dip);
+  if (!gfx::Display::HasForceDeviceScaleFactor())
+    display.set_device_scale_factor(device_scale_factor);
+  display.SetRotationAsDegree(device_info.GetRotationDegrees());
+  return display;
+}
+
 class ScreenAndroid : public Screen {
  public:
   ScreenAndroid() {}
 
   gfx::Point GetCursorScreenPoint() override { return gfx::Point(); }
 
   gfx::NativeWindow GetWindowUnderCursor() override {
     NOTIMPLEMENTED();
     return NULL;
   }
 
   gfx::NativeWindow GetWindowAtScreenPoint(const gfx::Point& point) override {
     NOTIMPLEMENTED();
     return NULL;
   }
 
   gfx::Display GetPrimaryDisplay() const override {
     gfx::DeviceDisplayInfo device_info;
-    const float device_scale_factor = device_info.GetDIPScale();
-    // Note: GetPhysicalDisplayWidth/Height() does not subtract window
-    // decorations etc. Use it instead of GetDisplayWidth/Height() when
-    // available.
-    const gfx::Rect bounds_in_pixels =
-        gfx::Rect(device_info.GetPhysicalDisplayWidth()
-                      ? device_info.GetPhysicalDisplayWidth()
-                      : device_info.GetDisplayWidth(),
-                  device_info.GetPhysicalDisplayHeight()
-                      ? device_info.GetPhysicalDisplayHeight()
-                      : device_info.GetDisplayHeight());
-    const gfx::Rect bounds_in_dip =
-        gfx::Rect(gfx::ToCeiledSize(gfx::ScaleSize(
-            bounds_in_pixels.size(), 1.0f / device_scale_factor)));
-    gfx::Display display(0, bounds_in_dip);
-    if (!gfx::Display::HasForceDeviceScaleFactor())
-      display.set_device_scale_factor(device_scale_factor);
-    display.SetRotationAsDegree(device_info.GetRotationDegrees());
-    return display;
+    return DisplayFromDeviceDisplayInfo(device_info);
   }
 
   gfx::Display GetDisplayNearestWindow(gfx::NativeView view) const override {
-    return GetPrimaryDisplay();
+    return DisplayFromDeviceDisplayInfo(
+        view->GetWindowAndroid()->GetDeviceDisplayInfo());
   }
 
   gfx::Display GetDisplayNearestPoint(const gfx::Point& point) const override {
     return GetPrimaryDisplay();
   }
 
   int GetNumDisplays() const override { return 1; }
 
   std::vector<gfx::Display> GetAllDisplays() const override {
     return std::vector<gfx::Display>(1, GetPrimaryDisplay());
@@ skipping 13 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScreenAndroid);
 };
 
 Screen* CreateNativeScreen() {
   return new ScreenAndroid;
 }
 
 }  // namespace gfx