Make WebView work for external displays (over Presentations).

ui/gfx/android/device_display_info.h

Index: ui/gfx/android/device_display_info.h
diff --git a/ui/gfx/android/device_display_info.h b/ui/gfx/android/device_display_info.h
index 74e0ada487507f05d3a5f8f8a9e6374eebf39654..1e589aab293ee77ee875f6c4ad8929c9a11200fb 100644
--- a/ui/gfx/android/device_display_info.h
+++ b/ui/gfx/android/device_display_info.h
@@ -8,6 +8,7 @@
 #include <jni.h>
 #include <string>
 
+#include "base/android/jni_android.h"
 #include "base/basictypes.h"
 #include "ui/gfx/gfx_export.h"
 
@@ -18,43 +19,62 @@ namespace gfx {
 class GFX_EXPORT DeviceDisplayInfo {
  public:
   DeviceDisplayInfo();
+  explicit DeviceDisplayInfo(jobject context);
   ~DeviceDisplayInfo();
 
   // Returns display height in physical pixels.
-  int GetDisplayHeight();
+  int GetDisplayHeight() const;
 
   // Returns display width in physical pixels.
-  int GetDisplayWidth();
+  int GetDisplayWidth() const;
 
   // Returns real display height in physical pixels.
   // This version does not subtract window decorations etc.
   // WARNING: This is only supported on JB-MR1 (sdk >= 17). Either
   //          check the SDK-level, or check for '0' being returned.
-  int GetPhysicalDisplayHeight();
+  int GetPhysicalDisplayHeight() const;
 
   // Returns real display width in physical pixels.
   // This version does not subtract window decorations etc.
   // WARNING: This is only supported on JB-MR1 (sdk >= 17). Either
   //          check the SDK-level, or check for '0' being returned.
-  int GetPhysicalDisplayWidth();
+  int GetPhysicalDisplayWidth() const;
 
   // Returns number of bits per pixel.
-  int GetBitsPerPixel();
+  int GetBitsPerPixel() const;
 
   // Returns number of bits per component.
-  int GetBitsPerComponent();
+  int GetBitsPerComponent() const;
 
   // Returns a scaling factor for Density Independent Pixel unit
   // (1.0 is 160dpi, 0.75 is 120dpi, 2.0 is 320dpi).
-  double GetDIPScale();
+  double GetDIPScale() const;
 
   // Smallest possible screen size in density-independent pixels.
-  int GetSmallestDIPWidth();
+  int GetSmallestDIPWidth() const;
 
   // Returns the display rotation angle from its natural orientation. Expected
   // values are one of { 0, 90, 180, 270 }.
   // See DeviceDispayInfo.java for more information.
-  int GetRotationDegrees();
+  int GetRotationDegrees() const;
+
+  // Registers methods with JNI and returns true if succeeded.
+  static bool RegisterDeviceDisplayInfo(JNIEnv* env);
+
+ private:
+  void FetchDisplayInfoFromJava(JNIEnv* env);
+
+  base::android::ScopedJavaGlobalRef<jobject> j_device_info_;
+
+  int display_height_;
+  int display_width_;
+  int physical_display_height_;
+  int physical_display_width_;
+  int bits_per_pixel_;
+  int bits_per_component_;
+  double dip_scale_;
+  int smallest_dip_width_;
+  int rotation_degrees_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DeviceDisplayInfo);