[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
hwui: Always enable the scissor while composing layer

Due to scissor optimization feature added in KK, scissor was disabled
all the time. Hence the undefined areas/region of textures are not
masking properly with GL_LINEAR filter mode.

Change-Id: Ifbbde2c67a4c01e45eda07ada709e066255fffcb
CRs-fixed: 645077
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>
hwui: Apply hwui qcom fixes to all adreno-bearing hardware

Even if the device doesn't fully use the qcom stack, changes to
libhwui are generally workarounds for adreno-specific issues and
apply across the board without other dependencies

Change-Id: I10455ebf09c1d00762b06e3c092398604bb39796