[Android] Remove unnecesary binder calls.

Rather than going through the WindowManager and Display to get
DisplayMetrics, use the instance hanging off the context. This saves
several extra IPCs and reduces time in these functions during startup by
~20ms.

NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/16093031

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@204079 0039d316-1c4b-4281-b951-d872f2087c98

ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java

@@ -7,7 +7,6 @@ package org.chromium.ui.gfx;
 import android.content.Context;
 import android.graphics.PixelFormat;
 import android.os.Build;
-import android.telephony.TelephonyManager;
 import android.util.DisplayMetrics;
 import android.view.Display;
 import android.view.WindowManager;
@@ -25,11 +24,13 @@ import org.chromium.base.JNINamespace;
 @JNINamespace("gfx")
 public class DeviceDisplayInfo {
 
-  private WindowManager mWinManager;
+
+  private final Context mAppContext;
+  private final WindowManager mWinManager;
 
   private DeviceDisplayInfo(Context context) {
-      Context appContext = context.getApplicationContext();
-      mWinManager = (WindowManager) appContext.getSystemService(Context.WINDOW_SERVICE);
+      mAppContext = context.getApplicationContext();
+      mWinManager = (WindowManager) mAppContext.getSystemService(Context.WINDOW_SERVICE);
   }
 
   /**
@@ -114,24 +115,12 @@ public class DeviceDisplayInfo {
       return getMetrics().density;
   }
 
-  /**
-   * @return Display refresh rate in frames per second.
-   */
-  @CalledByNative
-  public double getRefreshRate() {
-      double result = getDisplay().getRefreshRate();
-      // Sanity check.
-      return (result >= 61 || result < 30) ? 0 : result;
-  }
-
   private Display getDisplay() {
       return mWinManager.getDefaultDisplay();
   }
 
   private DisplayMetrics getMetrics() {
-      DisplayMetrics metrics = new DisplayMetrics();
-      getDisplay().getMetrics(metrics);
-      return metrics;
+      return mAppContext.getResources().getDisplayMetrics();
   }
 
   /**

ui/gfx/android/device_display_info.cc

@@ -58,13 +58,6 @@ double DeviceDisplayInfo::GetDIPScale() {
   return static_cast<double>(result);
 }
 
-double DeviceDisplayInfo::GetRefreshRate() {
-  JNIEnv* env = AttachCurrentThread();
-  jdouble result =
-      Java_DeviceDisplayInfo_getRefreshRate(env, j_device_info_.obj());
-  return static_cast<double>(result);
-}
-
 // static
 bool DeviceDisplayInfo::RegisterDeviceDisplayInfo(JNIEnv* env) {
   return RegisterNativesImpl(env);

ui/gfx/android/device_display_info.h

@@ -37,9 +37,6 @@ class UI_EXPORT DeviceDisplayInfo {
   // (1.0 is 160dpi, 0.75 is 120dpi, 2.0 is 320dpi).
   double GetDIPScale();
 
-  // Returns display refresh rate in number of frames per second.
-  double GetRefreshRate();
-
   // Registers methods with JNI and returns true if succeeded.
   static bool RegisterDeviceDisplayInfo(JNIEnv* env);