Optimize drawBitmapMesh using TRIANGLE_STRIP

Draw BitmapMesh using STRIP instead of TRIANGLES.
Depending on where the bottleneck is located in the pipeline,
there is a potential for saving two-thirds of the time spent rendering.
The speedup is due to avoiding redundant operations,
i.e., mapping each vertex four times to texture and color attribute,
sending each vertex twice to the GPU, vertex processing of GPU ...

In this patch:
1. Refactoring mesh using Strip.
2. Batch triangles by adding degenerate triangles.
3. Optimize computing positions of texture and color attribute.

Benchmark: Drawing Bitmap(1152x768 px) with 200x200 meshes
Performance is doubled (from 26.4 fps to 53 fps, Nexus10).
Memory footprint: only 17% of original method.
(from 240000 to 40401 vertices with xy, uv, rgba data.)

Change-Id: I08c5c20d981d88528ce7b02012feefae468d6ec4
Signed-off-by: kui.zheng <kui.zheng@arm.com>
Restore untrusted glStencilMask value on resume after functor

Fixes an issue where the stencil buffer is corrupted
(used in overdraw debugging, path clipping) when used in
conjunction with a HW accelerated WebView.

bug:15023700
bug:16465551

Change-Id: If201b503931380f7107a34e9a9a2f877a50f72b1
Use hidden API to validate APK chains

Bug: 13678484
Change-Id: I28dedab74b0e24d47ab9f2190298156c909e9d54
(cherry picked from commit 5a30e8a0ebb19852902361079b139ee160a53588)
inputdevices: update from aosp (master)

Change-Id: If5fb11c354ea0144cdae1434de4c536302dda5b3
[HWUI]: fix residual line on FrameBuffer

Symptom: If app applies animation to enlarge a bitmap, there will be an residual
         line on the screen

Root Cause: On platform which has Tile Rendering implementation (ex. Qualcomm
            CPU), startTiling() call will restrict the framebuffer region which
            GPU can affect. So the expansion of clear region by 1 will not take
            effect if startTiling region is not expanded.

Solution: Expand the startTiling region by 1, too.

Reproduce steps: Apply animation to enlarge (and then shrink) a bitmap icon.

Change-Id: I7b4a59e180daa29dbe909d9e11f4093ae1d7396f
[HWUI] Fix invisible views are still shown in popup window

Symptom: Invisible views are still shown in popup window

Root Cause: glClear isn't called if there is no draw command

Solution: Even if there is no draw command, it still calls glClear
          by startFrame().

Reproduce steps: App set one view in a popup window to invisible,
                 it will be still visible.

Change-Id: I36bc7b752434ad388fbb80ea63341ac778f48d35
Revert Update the layer's alpha value upon composition of the layer