[Android] Explicitly disable ScaleGestureDetector's "QuickScale" feature

With the latest Android SDK release, the platform ScaleGestureDetector provides
support for double-tap drag zoom.  This conflicts with the current double-tap
drag zoom implementation in ContentViewGestureHandler.  Explicitly disable this
feature until adoption of ScaleGestureDetector's QuickScale feature, preventing
issues if the Android API target is more recent than JB MR2.

BUG=331092

Review URL: https://codereview.chromium.org/122483002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242838 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242838
Fix scaling of hiDPI plugins in software composited mode

Previously the device scale that a plugin is painted at was not being accounted for when transforming the plugin layer in software composited mode. This takes that into account.

BUG=330948

Review URL: https://codereview.chromium.org/122163002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242839 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242839