[Android] Add scoped trace to ContentViewCore.updateFrameInfo

This method is taking a non-trivial amount of time during a typical scroll
sequence, so convert the instant trace into a proper scoped trace.

BUG=401204
NOTRY=true

Review URL: https://codereview.chromium.org/446063003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@287881 0039d316-1c4b-4281-b951-d872f2087c98

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

@@ -2276,7 +2276,7 @@ public class ContentViewCore
             float viewportWidth, float viewportHeight,
             float controlsOffsetYCss, float contentOffsetYCss,
             float overdrawBottomHeightCss) {
-        TraceEvent.instant("ContentViewCore:updateFrameInfo");
+        TraceEvent.begin("ContentViewCore:updateFrameInfo");
         // Adjust contentWidth/Height to be always at least as big as
         // the actual viewport (as set by onSizeChanged).
         final float deviceScale = mRenderCoordinates.getDeviceScaleFactor();
@@ -2341,6 +2341,7 @@ public class ContentViewCore
         if (mBrowserAccessibilityManager != null) {
             mBrowserAccessibilityManager.notifyFrameInfoInitialized();
         }
+        TraceEvent.end("ContentViewCore:updateFrameInfo");
     }
 
     @CalledByNative